Martha's Shack is Martha's home. It is located in the Pore, somewhat below the Deeps. The shack was first built by the Russian sailors whose submarine got sucked down Smoking Jean. Later, Martha's son Nathaniel enlarged it. Will, Chester, and Elliott are taken to the shack to recuperate in Freefall.
The main building consists of a pioneer-style building made with wood and metal. Will noticed how old the planking looks and learns that Nathaniel helped improve the shack with wood he found from a galleon sucked under.
There are other buildings around the main shack, including storage sheds and a grave site for Nathaniel.