Dismal Key  Dismal Key is a small island, part of the Ten Thousand Islands archipelago in the Gulf of Mexico off the coast of Florida. The island is artificial, constructed by people of the Glades culture. Construction of the island proceeded in stages over some 1,500 years following the end of the Archaic period in Florida. Occupation probably ended a couple of centuries before the arrival of Europeans in Florida. Dismal Key was occupied by several hermits in the 20th century. The southwest coast of Florida has many large artificial structures known as shell works, made of shells piled up by human activity. Shell works are found from Charlotte Harbor southward through the Ten Thousand Islands. Many of the shell works are surrounded by water, forming artificial islands, often called keys. The shell works were the sites of villages, occupied by people who depended primarily on fishing, but also hunted and gathered wild foods. Shells works have complex structures, apparently designed to separate spaces by use; domestic, public and sacred. The northern part of the range in which shell works are found, from Charlotte Harbor through Estero Bay, was occupied by people of the Caloosahatchee culture. The southern part of the range, including Marco Island and the Ten Thousand Islands, was occupied by people of the Ten Thousand Islands region of the Glades culture. Both the Caloosahatchee culture area and the Ten Thousand Islands region of the Glades culture area were occupied by the Calusa people at the time of first contact with Europeans. Archaeological evidence indicates that artifacts in the Ten Thousand Islands region changed from resembling those of the Glades culture to resembling those of the Caloosahatchee culture around 1300, indicating absorption by or strong influence from the Calusa. Schwadron notes that many of the shell works sites in the Ten Thousand Islands appear to have been abandoned shortly before 1300, and suggests that the people of those sites may have migrated into Calusa territory. Dismal Key is about in size. The entire key above water consists of shell works, shells piled up by human activity, with various apparently designed features. The key is crescent shaped, and roughly bilaterally symmetric. The structure of the shell works on Dismal Key resembles that of other shell works in the Ten Thousand Islands, including Fakahatchee Key, Russell Key, Sandfly Key, Key Marco and Chokoloskee Island, suggesting a common plan. A "c"-shaped shell ring of about in width and up to high is located in the open end of the shell works on Dismal Key.