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Animal Crossing
ACNH 3.0 Slumber Map Sizes & Dimensions - Layouts, Limits, Features & How to Choose
11/7/2025 10:43:56 AM
Nintendo revealed the 3.0 update that’s coming to Animal Crossing New Horizons early next year! This free content update is bringing with it a bunch of new content, new items, new facilities, and features, including Slumber Islands! In this ACNH 3.0 Slumber map guide, we'll analyze the new types, sizes, limits, features, and mechanics.
Animal Crossing 3.0 Slumber Island Map Guide
Slumber Islands is likely to be released early next year in the Animal Crossing New Horizons 3.0 update. It adds three additional “dream” or “secondary” islands for the player. These appear to be customizable extra islands, separate from your main island — ideal for creative builds, theme challenges, or alternate layouts. There are 3 available sizes, and each comes with its own terrain limits, structures, and features. Without further ado, dive into these Animal Crossing New Horizons 3.0 slumber maps sizes and layouts.
ACNH 3.0 Slumber Map Sizes
The ACNH Slumbermap feature from Luna offers us 3 extra Islands available in 3 different sizes, each with its own limitations! You can choose small islands, medium islands or large islands! But how small and how large are we actually talking here?
1. Small Slumber Island
Size & Layout
Size: 1 acre total.
Dimensions: Roughly 16 × 16 tiles (256 tiles total).
Land-to-sand ratio: About 50/50 (half land, half beach).
Extremely compact, ideal for minimalist or themed challenges.
Features & Limitations
| Feature | Availability |
|---|---|
| Dock | None |
| Rocks on beaches | None (except northern border rocks) |
| Peninsula | None |
| Secret Beach | None |
| River | Optional single river (East or West) |
| River Mouths | One (if a river is chosen) |
| Slumber Port (entrance) | Always central |
Notes
Great for creative challenges, themed micro builds, or dioramas.
Ideal for fast decoration ideas due to limited space.
No fish mentioned in the trailer — only bugs appear.
2. Medium Slumber Island
Size & Layout
Size: 4 acres (2×2 acres grid).
Significantly larger than Small, still compact.
Roughly 4× the area of the Small island.
Terraformable area: 4 acres of land.
Features & Limitations
| Feature | Availability |
|---|---|
| Dock | None |
| Beach Rocks | Present |
| Peninsula | None |
| Secret Beach | None |
| River Mouths | Always present (East, West, SE, or SW options) |
| Port (Entrance) | Not central (usually near a river mouth) |
| Cliffs | Some preset cliffs (but irrelevant due to terraforming) |
Notes
Offers more freedom than the Small Island.
Still lacks certain “normal” island features like docks and peninsulas.
Has guaranteed river mouths.
Perfect for cottagecore or medium-sized creative builds.
Port placement depends on map variation.
3. Large Slumber Island
Size & Layout
Size: 20 acres (4×5 acre grid) — equivalent to a full-size normal island.
Same size as your main ACNH island.
Features & Limitations
| Feature | Availability |
|---|---|
| Dock | None |
| Peninsula | Optional (some maps have 1–2) |
| Secret Beach | Optional (some maps have none, some one, some two) |
| River Mouths | Always two (East/South, West/South, or double South) |
| Beach Rocks | Present |
| Port (Entrance) | Always central |
| Cliffs | Included, customizable with terraforming |
Notes
Full-scale creative space like your main island.
Great for city builds or large theme parks.
Has customizable terrain and multiple map options.
A few variations allow for pre-flattened maps — ready for large-scale projects.
Shared Traits & Global Limitations (All Island Sizes)
| System | Description |
|---|---|
| Luna’s Port (Entrance) | Permanent and cannot be moved. |
| Beach Rocks & River Mouths | Fixed — cannot be relocated or deleted. |
| Terraforming | Fully available (cliffs, rivers, etc.). |
| House Placement | The player’s house may be fixed near the Port (currently suspected to be immovable). |
| Construction | Lloid is available for slopes and stairs, but not for moving the player’s home. |
| Creatures | Bugs are confirmed to appear, but no fish seen in trailers. |
| Map Layouts | Each island size likely has 4 preset layouts only — not procedurally generated like the original. |
Best ACNH 3.0 Slumber Map Dimensions & Sizes
| Island Type | Size (acres) | Best For | Key Features | Key Limitations |
|---|---|---|---|---|
| Small | 1 (16×16 tiles) | Mini builds, challenges, fast decorating | Simple, symmetrical, cute | No dock, no secret beach, tiny space |
| Medium | 4 (2×2 grid) | Compact creative projects | Has beach rocks and river mouths | No dock, no peninsula |
| Large | 20 (4×5 grid / full island) | Full builds, city or resort layouts | Full island size, secret beach, peninsula options | No dock, fixed features |
The Slumber Islands appear to be secondary “dream” islands that the player can visit or decorate, separate from their main island — possibly through Luna’s dream portal. They may not support normal villager population or standard island progression (since no dock = no Kapp’n or boat tours).
Likely designed for creative builders and showcase creators. The absence of fish might indicate no full ecology simulation, making these islands lighter for performance and decoration-focused.
