diff --git a/admin/inertia/components/maps/MarkerPanel.tsx b/admin/inertia/components/maps/MarkerPanel.tsx
index 025b37c..f7a58b8 100644
--- a/admin/inertia/components/maps/MarkerPanel.tsx
+++ b/admin/inertia/components/maps/MarkerPanel.tsx
@@ -2,14 +2,17 @@ import { useMemo, useState } from 'react'
 import {
   IconEye,
   IconEyeOff,
+  IconList,
   IconMapPin,
   IconMapPinFilled,
+  IconSitemap,
   IconTrash,
   IconX,
 } from '@tabler/icons-react'
 import * as TablerIcons from '@tabler/icons-react'
 import type { IconProps } from '@tabler/icons-react'
 import type { ComponentType } from 'react'
+
 import { PIN_COLORS } from '~/hooks/useMapMarkers'
 import type { MapMarker } from '~/hooks/useMapMarkers'
 
@@ -24,6 +27,19 @@ interface MarkerPanelProps {
 
 type SortField = 'name' | 'color' | 'visibility' | 'icon'
 type SortDirection = 'asc' | 'desc'
+type ViewMode = 'list' | 'tree'
+
+type ColorSortValue = {
+  bucket: number
+  hue: number
+  lightness: number
+}
+
+type MarkerGroup = {
+  key: string
+  label: string
+  markers: MapMarker[]
+}
 
 const normalizeColorHex = (color: string, customColor?: string | null) => {
   if (customColor) return customColor
@@ -32,7 +48,7 @@ const normalizeColorHex = (color: string, customColor?: string | null) => {
   return preset?.hex ?? color
 }
 
-const getColorSortValue = (color: string, customColor?: string | null) => {
+const getColorSortValue = (color: string, customColor?: string | null): ColorSortValue => {
   const hex = normalizeColorHex(color, customColor).replace('#', '')
 
   if (!/^[0-9a-fA-F]{6}$/.test(hex)) {
@@ -69,6 +85,26 @@ const getColorSortValue = (color: string, customColor?: string | null) => {
   }
 }
 
+const getHueGroupLabel = ({ bucket, hue, lightness }: ColorSortValue) => {
+  if (bucket === 0) {
+    return lightness < 0.34
+      ? 'Grayscale — Dark'
+      : lightness < 0.67
+        ? 'Grayscale — Mid'
+        : 'Grayscale — Light'
+  }
+
+  if (bucket === 2) return 'Other colors'
+
+  if (hue < 30 || hue >= 330) return 'Red'
+  if (hue < 60) return 'Orange'
+  if (hue < 90) return 'Yellow'
+  if (hue < 150) return 'Green'
+  if (hue < 210) return 'Cyan'
+  if (hue < 270) return 'Blue'
+  return 'Purple'
+}
+
 const resolveMarkerIcon = (icon?: string | null): ComponentType<IconProps> => {
   if (!icon) return IconMapPinFilled
 
@@ -77,6 +113,32 @@ const resolveMarkerIcon = (icon?: string | null): ComponentType<IconProps> => {
   return Icon ? (Icon as ComponentType<IconProps>) : IconMapPinFilled
 }
 
+const getMarkerGroup = (marker: MapMarker, sortField: SortField) => {
+  if (sortField === 'name') {
+    const firstLetter = marker.name.trim().charAt(0).toUpperCase()
+
+    if (!firstLetter || !/[A-Z]/.test(firstLetter)) {
+      return { key: '#', label: '#' }
+    }
+
+    return { key: firstLetter, label: firstLetter }
+  }
+
+  if (sortField === 'color') {
+    const label = getHueGroupLabel(getColorSortValue(marker.color, marker.customColor))
+    return { key: label, label }
+  }
+
+  if (sortField === 'icon') {
+    const label = marker.icon || 'Default pin'
+    return { key: label, label }
+  }
+
+  return marker.visible
+    ? { key: 'visible', label: 'Visible' }
+    : { key: 'hidden', label: 'Hidden' }
+}
+
 export default function MarkerPanel({
                                       markers,
                                       onDelete,
@@ -89,6 +151,8 @@ export default function MarkerPanel({
   const [searchQuery, setSearchQuery] = useState('')
   const [sortField, setSortField] = useState<SortField>('name')
   const [sortDirection, setSortDirection] = useState<SortDirection>('asc')
+  const [viewMode, setViewMode] = useState<ViewMode>('list')
+  const [collapsedGroups, setCollapsedGroups] = useState<Set<string>>(new Set())
 
   const sortDirectionLabel =
     sortField === 'name'
@@ -107,7 +171,7 @@ export default function MarkerPanel({
             ? 'Hidden first'
             : 'Visible first'
 
-  const visibleMarkers = useMemo(() => {
+  const filteredAndSortedMarkers = useMemo(() => {
     const query = searchQuery.trim().toLowerCase()
 
     return [...markers]
@@ -119,14 +183,11 @@ export default function MarkerPanel({
         const result =
           sortField === 'name'
             ? a.name.localeCompare(b.name, undefined, { sensitivity: 'base' })
-
             : sortField === 'visibility'
               ? Number(a.visible) - Number(b.visible)
-
               : sortField === 'icon'
                 ? (a.icon ? 1 : 0) - (b.icon ? 1 : 0) ||
-                (a.icon ?? '').localeCompare(b.icon ?? '')
-
+                (a.icon ?? '').localeCompare(b.icon ?? '', undefined, { sensitivity: 'base' })
                 : (() => {
                   const aColor = getColorSortValue(a.color, a.customColor)
                   const bColor = getColorSortValue(b.color, b.customColor)
@@ -142,6 +203,129 @@ export default function MarkerPanel({
       })
   }, [markers, searchQuery, sortField, sortDirection])
 
+  const markerGroups = useMemo(() => {
+    const groups = new Map<string, MarkerGroup>()
+
+    filteredAndSortedMarkers.forEach((marker) => {
+      const group = getMarkerGroup(marker, sortField)
+
+      if (!groups.has(group.key)) {
+        groups.set(group.key, {
+          key: group.key,
+          label: group.label,
+          markers: [],
+        })
+      }
+
+      groups.get(group.key)?.markers.push(marker)
+    })
+
+    return Array.from(groups.values()).sort((a, b) => {
+      const result = a.label.localeCompare(b.label, undefined, { sensitivity: 'base' })
+      return sortDirection === 'asc' ? result : -result
+    })
+  }, [filteredAndSortedMarkers, sortField, sortDirection])
+
+  const allGroupsCollapsed =
+    markerGroups.length > 0 && markerGroups.every((group) => collapsedGroups.has(group.key))
+
+  const allFilteredMarkersVisible =
+    filteredAndSortedMarkers.length > 0 &&
+    filteredAndSortedMarkers.every((marker) => marker.visible)
+
+  const toggleGroupCollapsed = (groupKey: string) => {
+    setCollapsedGroups((prev) => {
+      const next = new Set(prev)
+
+      if (next.has(groupKey)) {
+        next.delete(groupKey)
+      } else {
+        next.add(groupKey)
+      }
+
+      return next
+    })
+  }
+
+  const collapseAllGroups = () => {
+    setCollapsedGroups(new Set(markerGroups.map((group) => group.key)))
+  }
+
+  const expandAllGroups = () => {
+    setCollapsedGroups(new Set())
+  }
+
+  const setGroupVisibility = (group: MarkerGroup, visible: boolean) => {
+    group.markers.forEach((marker) => {
+      if (marker.visible !== visible) {
+        onToggleVisibility(marker.id, visible)
+      }
+    })
+  }
+
+  const setAllMarkerVisibility = (visible: boolean) => {
+    filteredAndSortedMarkers.forEach((marker) => {
+      if (marker.visible !== visible) {
+        onToggleVisibility(marker.id, visible)
+      }
+    })
+  }
+
+  const renderMarkerRow = (marker: MapMarker) => {
+    const MarkerIcon = resolveMarkerIcon(marker.icon)
+
+    return (
+      <li
+        key={marker.id}
+        className={`group flex items-center gap-2 border-b border-border-subtle px-3 py-2 transition-colors last:border-b-0 ${
+          marker.id === selectedMarkerId ? 'bg-desert-green/10' : 'hover:bg-surface-secondary'
+        } ${marker.visible ? '' : 'opacity-60'}`}
+      >
+        <MarkerIcon
+          size={16}
+          className="shrink-0"
+          style={{
+            color: normalizeColorHex(marker.color, marker.customColor),
+          }}
+        />
+
+        <button
+          type="button"
+          onClick={() => {
+            onSelect(marker.id)
+            onFlyTo(marker.longitude, marker.latitude)
+          }}
+          className="min-w-0 flex-1 text-left"
+          title={marker.name}
+        >
+          <p className="truncate text-sm font-medium text-text-primary">{marker.name}</p>
+        </button>
+
+        <button
+          type="button"
+          onClick={(event) => {
+            event.stopPropagation()
+            onToggleVisibility(marker.id, !marker.visible)
+          }}
+          className="shrink-0 rounded p-1 text-text-muted transition-colors hover:bg-surface-secondary hover:text-text-primary"
+          title={marker.visible ? 'Hide pin' : 'Show pin'}
+          aria-label={marker.visible ? 'Hide pin' : 'Show pin'}
+        >
+          {marker.visible ? <IconEye size={14} /> : <IconEyeOff size={14} />}
+        </button>
+
+        <button
+          type="button"
+          onClick={() => onDelete(marker.id)}
+          className="shrink-0 rounded p-1 text-text-muted opacity-0 transition-all hover:bg-surface-secondary hover:text-desert-red group-hover:opacity-100"
+          title="Delete pin"
+        >
+          <IconTrash size={14} />
+        </button>
+      </li>
+    )
+  }
+
   if (!open) {
     return (
       <button
@@ -196,10 +380,63 @@ export default function MarkerPanel({
           className="block w-full rounded border border-border-default bg-surface-primary px-2 py-1 text-sm text-text-primary placeholder:text-text-muted focus:border-desert-green focus:outline-none"
         />
 
+        <div className="flex gap-2">
+          <button
+            type="button"
+            onClick={() => setViewMode('list')}
+            title="List view"
+            className={`flex flex-1 items-center justify-center gap-1 rounded px-2 py-1 text-xs transition-colors ${
+              viewMode === 'list'
+                ? 'bg-[#424420] text-white'
+                : 'bg-surface-primary text-text-secondary hover:bg-surface-secondary'
+            }`}
+          >
+            <IconList size={14} />
+            List
+          </button>
+
+          <button
+            type="button"
+            onClick={() => setViewMode('tree')}
+            title="Tree view"
+            className={`flex flex-1 items-center justify-center gap-1 rounded px-2 py-1 text-xs transition-colors ${
+              viewMode === 'tree'
+                ? 'bg-[#424420] text-white'
+                : 'bg-surface-primary text-text-secondary hover:bg-surface-secondary'
+            }`}
+          >
+            <IconSitemap size={14} />
+            Tree
+          </button>
+        </div>
+
+        {viewMode === 'tree' && (
+          <div className="flex gap-2">
+            <button
+              type="button"
+              onClick={allGroupsCollapsed ? expandAllGroups : collapseAllGroups}
+              className="flex-1 rounded bg-[#424420] px-2 py-1 text-xs text-white hover:bg-[#525530]"
+            >
+              {allGroupsCollapsed ? 'Expand all' : 'Collapse all'}
+            </button>
+
+            <button
+              type="button"
+              onClick={() => setAllMarkerVisibility(!allFilteredMarkersVisible)}
+              className="flex-1 rounded bg-[#424420] px-2 py-1 text-xs text-white hover:bg-[#525530]"
+            >
+              {allFilteredMarkersVisible ? 'Hide all' : 'Show all'}
+            </button>
+          </div>
+        )}
+
         <div className="flex gap-2">
           <select
             value={sortField}
-            onChange={(e) => setSortField(e.target.value as SortField)}
+            onChange={(e) => {
+              setSortField(e.target.value as SortField)
+              setCollapsedGroups(new Set())
+            }}
             className="flex-1 rounded border border-border-default bg-surface-primary px-2 py-1 text-xs text-text-primary focus:border-desert-green focus:outline-none"
           >
             <option value="name">Sort by name</option>
@@ -218,73 +455,55 @@ export default function MarkerPanel({
         </div>
       </div>
 
-      <div className="max-h-[calc(100vh-240px)] overflow-y-auto">
+      <div className="max-h-[calc(100vh-280px)] overflow-y-auto">
         {markers.length === 0 ? (
           <div className="px-3 py-6 text-center">
             <IconMapPinFilled size={24} className="mx-auto mb-2 text-text-muted" />
             <p className="text-sm text-text-muted">Click anywhere on the map to drop a pin</p>
           </div>
-        ) : visibleMarkers.length === 0 ? (
+        ) : filteredAndSortedMarkers.length === 0 ? (
           <div className="px-3 py-6 text-center">
             <p className="text-sm text-text-muted">No pins match your search.</p>
           </div>
+        ) : viewMode === 'list' ? (
+          <ul>{filteredAndSortedMarkers.map(renderMarkerRow)}</ul>
         ) : (
-          <ul>
-            {visibleMarkers.map((marker) => {
-              const MarkerIcon = resolveMarkerIcon(marker.icon)
+          <div>
+            {markerGroups.map((group) => {
+              const isCollapsed = collapsedGroups.has(group.key)
+              const allVisible = group.markers.every((marker) => marker.visible)
+              const someVisible = group.markers.some((marker) => marker.visible)
 
               return (
-                <li
-                  key={marker.id}
-                  className={`group flex items-center gap-2 border-b border-border-subtle px-3 py-2 transition-colors last:border-b-0 ${
-                    marker.id === selectedMarkerId ? 'bg-desert-green/10' : 'hover:bg-surface-secondary'
-                  } ${marker.visible ? '' : 'opacity-60'}`}
-                >
-                  <MarkerIcon
-                    size={16}
-                    className="shrink-0"
-                    style={{
-                      color: normalizeColorHex(marker.color, marker.customColor),
-                    }}
-                  />
+                <div key={group.key} className="border-b border-border-subtle last:border-b-0">
+                  <div className="flex items-center gap-2 bg-surface-secondary/70 px-3 py-1.5">
+                    <button
+                      type="button"
+                      onClick={() => toggleGroupCollapsed(group.key)}
+                      className="min-w-0 flex-1 text-left text-xs font-semibold text-text-primary"
+                      title={group.label}
+                    >
+                      <span className="truncate">
+                        {isCollapsed ? '▸' : '▾'} {group.label} ({group.markers.length})
+                      </span>
+                    </button>
 
-                  <button
-                    type="button"
-                    onClick={() => {
-                      onSelect(marker.id)
-                      onFlyTo(marker.longitude, marker.latitude)
-                    }}
-                    className="min-w-0 flex-1 text-left"
-                    title={marker.name}
-                  >
-                    <p className="truncate text-sm font-medium text-text-primary">{marker.name}</p>
-                  </button>
+                    <button
+                      type="button"
+                      onClick={() => setGroupVisibility(group, !allVisible)}
+                      className="shrink-0 rounded p-1 text-text-muted transition-colors hover:bg-surface-primary hover:text-text-primary"
+                      title={allVisible ? 'Hide all pins in group' : 'Show all pins in group'}
+                      aria-label={allVisible ? 'Hide all pins in group' : 'Show all pins in group'}
+                    >
+                      {allVisible || someVisible ? <IconEye size={14} /> : <IconEyeOff size={14} />}
+                    </button>
+                  </div>
 
-                  <button
-                    type="button"
-                    onClick={(event) => {
-                      event.stopPropagation()
-                      onToggleVisibility(marker.id, !marker.visible)
-                    }}
-                    className="shrink-0 rounded p-1 text-text-muted transition-colors hover:bg-surface-secondary hover:text-text-primary"
-                    title={marker.visible ? 'Hide pin' : 'Show pin'}
-                    aria-label={marker.visible ? 'Hide pin' : 'Show pin'}
-                  >
-                    {marker.visible ? <IconEye size={14}/> : <IconEyeOff size={14}/>}
-                  </button>
-
-                  <button
-                    type="button"
-                    onClick={() => onDelete(marker.id)}
-                    className="shrink-0 rounded p-1 text-text-muted opacity-0 transition-all hover:bg-surface-secondary hover:text-desert-red group-hover:opacity-100"
-                    title="Delete pin"
-                  >
-                    <IconTrash size={14}/>
-                  </button>
-                </li>
+                  {!isCollapsed && <ul>{group.markers.map(renderMarkerRow)}</ul>}
+                </div>
               )
             })}
-          </ul>
+          </div>
         )}
       </div>
     </div>