Island Hideaway Structures
There are three building categories for the Island Sanctuary. They are "Cabin & Fields", "Processing Facilities", and "Landmarks".
Cabin & Fields
Cabins
The hideaway can have one Cabin, unlocked at Sanctuary Rank 1. The Cabin allows players to sell gathered items for those Islander's Cowries (
) and Seafarer's Cowries (
), as well as spending those currencies for attire, hairstyles, minions, mounts, etc.
Upgraded Cabins unlock upgrades for the Pasture and Cropland.
| Building | Unlock Rank | Build Time | Island EXP | Materials |
|---|---|---|---|---|
 Cozy Cabin I |
1 | None | 750 |
10 |
 Cozy Cabin II |
4 | None | 1,755 |
10 |
 Cozy Cabin III |
7 | None | 2,565 |
10 |
 Cozy Cabin IV |
13 | None | 7,500 |
15 |
 Cozy Cabin V |
17 | None | 13,200 |
15 |
Cropland
The hideaway can have one Cropland, unlocked at Rank 2. The Cropland allows players to grow Produce from Produce Starters (seeds or sets).
Upgraded Croplands provide additional plots for produce, and allows automation at upgrade III.
| Building | Unlock Rank | Build Time | Island EXP | Materials | Maximum Crops |
|---|---|---|---|---|---|
| Cropland I | 2 | None | 0 | Free | 5 |
| Cropland II | 4 | 2 hours | 0 | 1,000 Seafarer's Cowries |
10 |
| Cropland III | 7 | 4 hours | 0 | 1,500 Seafarer's Cowries |
20 |
Pastures
The hideaway can have one Pasture, unlocked at Rank 2. The Pasture allows players to gather Leavings from animals.
Upgraded Pastures hold additional animals, and allows automation at upgrade III.
| Building | Unlock Rank | Build Time | Island EXP | Materials | Maximum Animals |
|---|---|---|---|---|---|
| Pasture I | 2 | None | 0 | Free | 5 |
| Pasture II | 4 | 2 hours | 0 | 1,000 Seafarer's Cowries |
10 |
| Pasture III | 7 | 4 hours | 0 | 1,500 Seafarer's Cowries |
20 |
Processing Facilities
Workshops
The hideaway can have a maximum of four workshops: up to two at sanctuary rank 3, up to three beginning at rank 5, and up to four beginning at rank 15 (after Pathfinder Mk III/VI clears more plots).
Each workshop allows mammets to create handicrafts, which are exported for Seafarer's Cowries () when completed.
Upgraded Workshops increase the value of their handicrafts.
| Building | Unlock Rank | Build Time | Island EXP | Materials | Effect |
|---|---|---|---|---|---|
 Workshop I |
3 | None (first) 1-2 hours (others) |
1,425 |
10 |
|
 Workshop II |
6 | 6-7 hours | 2,300 |
15 |
10% higher yield of Seafarer's Cowries |
 Workshop III |
8 | 11-12 hours | 2,760 |
15 |
20% higher yield of Seafarer's Cowries |
 Workshop IV |
14 | 11-12 hours | 5,225 |
15 |
30% higher yield of Seafarer's Cowries |
 Workshop V |
19 | 11-12 hours | 12,000 |
15 |
40% higher yield of Seafarer's Cowries |
Granaries
The hideaway can have a maximum of 2 Granaries, both of which are available when Granaries unlock at Rank 5.
Each workshop allows mammets to go on expeditions to forage for various Normal materials, and a fixed amount of Rare materials which cannot otherwise be gathered on the island.
Upgraded Granaries yield more Rare materials from expeditions.
| Building | Unlock Rank | Build Time | Island EXP | Materials | Rare Material Yield |
|---|---|---|---|---|---|
 Granary I |
5 | 1-2 hours | 1,425 |
10 |
2 |
 Granary II |
6 | 6-7 hours | 2,300 |
15 |
3 |
 Granary III |
8 | 11-12 hours | 2,760 |
15 |
4 |
 Granary IV |
13 | 11-12 hours | 4,090 |
15 |
5 |
 Granary V |
18 | 11-12 hours | 8,400 |
15 |
6 |
Landmarks
The hideaway can have a maximum of 5 Landmarks. The first Landmark plot becomes available at Rank 4, second at Rank 5, third at Rank 7, fourth at Rank 9, and fifth at Rank 15.
Each constructed landmark increases the maximum Workshop Groove (to 15/20/25/35/45). Workshop Groove improves the value of Workshop Isleworks Handicrafts.
EXP obtained from initially constructing a landmark on a vacant plot is based on the number of existing landmarks: 1620 (0), 1800 (1), 1995 (2), 2460 (3), and 4550 (4). The EXP values listed in the below table are EXP from replacing a present landmark with the indicated one.
When placing a landmark, players can rotate where it is facing in 90 degree increments.
† A Water Otter Fountain Permit is required for the construction of the Water Otter Fountain. The Water Otter Fountain is not required to fill all Landmark slots.
This permit can be obtained from the Horrendous Hoarder in The Cozy Cabin in exchange for the following items (from Level 90★★★ Expert Crafting, requires Master Recipes X books). These items can also be purchased from the Market Board, although usually for an expensive price.
| Items Required for Turn in | Crafted by | Materials to Craft 2x Items |
|---|---|---|
2  Water Otter Fountain Hardware |
   |
|
2  Water Otter Fountain Resin |
  |
|
2  Water Otter Fountain Lumber |
   |
2 |
‡An Uncharted Course Construction Permit is required for the construction of the Uncharted Course. The Uncharted Course is not required to fill all Landmark slots.
After completion of 
An Ideal Marriage, this permit can be obtained from the Horrendous Hoarder in The Cozy Cabin in exchange for the following items (from Level 90★★★★ Expert Crafting, requires Master Recipes X books). These items can also be purchased from the Market Board, although usually for an expensive price.
| Items Required for Turn in | Crafted by | Materials to Craft 2x Items |
|---|---|---|
2  Uncharted Course Hardware |
|
2 |
2  Uncharted Course Resin |
|
2 |
2  Uncharted Course Lumber |
|
2 |
††An Aetherial Arbor Permit is required for the construction of the Aetherial Arbor. The Uncharted Course is not required to fill all Landmark slots.
After completion of The Sweetest Thing, this permit can be obtained from the Horrendous Hoarder in The Cozy Cabin in exchange for the following items (from Level 90★★★★★ Expert Crafting, requires Master Recipes X books). These items can also be purchased from the Market Board, although usually for an expensive price.
| Items Required for Turn in | Crafted by | Materials to Craft 2x Items |
|---|---|---|
2  Aetherial Arbor Hardware |
|
2 |
2  Aetherial Arbor Resin |
|
2 |
2  Aetherial Arbor Lumber |
|
2 |
Pathfinder Hideaway Expansions
The Pathfinder mammet expands the land available in the hideaway for constructing Processing Facilities and Landmarks. They are marked as 
on the map.
| Pathfinder | Unlock Rank | Coordinates | Build Time | Island EXP | Unlocks | Materials |
|---|---|---|---|---|---|---|
| Pathological Pathfinder Mk. I | 1 | (x12.6, y29.0) | None | 1,520 | Facility I & II slots | Free |
| Pathological Pathfinder Mk. II | 4 | (x12.6, y26.8) | None | 2,025 | Landmark I slot |  Basic Mammet-sized Builder's Tools 500 Seafarer's Cowries
|
| Pathological Pathfinder Mk. III | 5 | (x12.9, y29.4) | None | 2,160 | Facility III & IV slots Landmark II slot |
 Better Mammet-sized Builder's Tools 1,000 Seafarer's Cowries
|
| Pathological Pathfinder Mk. IV | 7 | (x14.2, y30.0) | None | 2,565 | Facility V slot Landmark III slot |
 Best Mammet-sized Builder's Tools 1,500 Seafarer's Cowries
|
| Pathological Pathfinder Mk. V | 9 | (x14.9, y29.4) | None | 3,280 | Landmark IV slot |  Bestest Mammet-sized Builder's Tools 3,000 Seafarer's Cowries
|
| Pathological Pathfinder Mk. VI | 15 | (x15.1, y30.3) | None | 4,875 | Facility VI slot Landmark V slot |
 Bestestest Mammet-sized Builder's Tools 3,000 Seafarer's Cowries
|