This work is a description and comparative analysis of otter shelters for three distinct environments, a freshwater lake, a coastal island, and a river. The original disposition of the rocks favors the formation of semi-closed internal environments, sometimes connected, and frequently divided in compartments. The structure created and the disposition of the internal and external spaces appears to be important in determining the comfort of the animal as related to temperature and ventilation. Otter conservation along the coastal region of Santa Catarina state depends on the conservation of the Atlantic Rain Forest.