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 |
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 3 Workshops. Two are available when Workshops unlock at Rank 3, and the third becomes available at Rank 5.
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 |
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 |
Landmarks
The hideaway can have a maximum of 4 Landmarks. The first Landmark plot becomes available at Rank 4, second at Rank 5, third at Rank 7, and fourth at Rank 9.
Each constructed landmark increases the maximum Workshop Groove (to 15/20/25/35). Workshop Groove improves the value of Workshop Isleworks Handicrafts.
| Building | Unlock Rank | Build Time | Island EXP | Materials |
|---|---|---|---|---|
 Quixotic Windmill |
3 | 11-12 hours | ?? |
15 |
 Towering Tree Fort |
3 | 11-12 hours | ?? |
15 |
 Boiling Bathhouse |
5 | 11-12 hours | 1,995 |
15 |
 Lominsan Lighthouse |
9 | 11-12 hours | 2,460 |
15 |
 Water Otter Fountain |
9† | 11-12 hours | ?? |
15 |
† 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):
| 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 |
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 | Build Time | Island EXP | Unlocks | Materials |
|---|---|---|---|---|---|
| Pathfinder Mk I | 1 | None | ?? | Facility I & II slots | Free |
| Pathfinder Mk II | 4 | None | ?? | Landmark I slot |  Basic Mammet-sized Builder's Tools 500 Seafarer's Cowries
|
| Pathfinder Mk III | 5 | None | ?? | Facility III & IV slots Landmark II slot |
 Better Mammet-sized Builder's Tools 1,000 Seafarer's Cowries
|
| Pathfinder Mk IV | 7 | None | ?? | Facility V slot Landmark III slot |
 Best Mammet-sized Builder's Tools 1,500 Seafarer's Cowries
|
| Pathfinder Mk V | 9 | None | 3,280 | Landmark IV slot |  Bestest Mammet-sized Builder's Tools 3,000 Seafarer's Cowries
|
References
u/Sewer-Rat's Island Sanctuary Comprehensive Guide