This is what it looks like on the outside.
Interior is unfortunately a bit small than expected.
Farming Space, Green Coral Polyp used for size comparison
What it looks like when decorated
Where to Obtain:
Available from Eternal Awakening Pack ($250) released on Sept 16, 2015. It needs a 28×28 plot and requires 30 Stone Packs, 10 Lumber Packs, and 10 Iron Packs to build.