Found in Mt Snowpeak Summit.
This is the Royal Family of Castelle's holiday house. It also acts as an Inn so you can rest here. Unlike Inns or beds, time doesn't pass when you rest here. This can be useful, when collecting ores or lumber and needing to recover HP or SP without causing all deposits or trees to regenerate.
Other than one plot related event, this cabin serves no other purpose other than to be a free rest spot on the mountain. You won't get any Bliss points for resting here, unlike all other Inns in Reveria.