Mound Key Archaeological State Park

Mound Key is what the Calusa built instead of a city: an island in Estero Bay engineered from shells, fish bone and daily refuse into mounds more than 30 feet high, threaded with canals, causeways and watercourt features. The Calusa, a fishing-and-gathering chiefdom that dominated southwest Florida for over two thousand years, are believed to have made this their ceremonial center when Spanish explorers arrived in the early 1500s; the mission San Antonio de Carlos stood here in 1566. The Calusa engineered a fish-based society in an estuary, and research keeps proving it: a 2024 study of porcupine fish deposits dated AD 1000 to 1600 found no spines at all, suggesting the parts were processed into products rather than simply eaten.

The Calusa polity was gone by the eighteenth century, its language unrecorded, and the island passed through the hands of the Koreshan Unity commune, which farmed the shell mounds in the early twentieth century. Today it is a Florida state park reachable only by boat, a constructed landscape of the dead and the living estuary alike.

Visiting

The Florida State Parks page covers access: open sunrise to sunset, no fee, boat only, typically launched from Koreshan State Park or Lovers Key; a .75-mile interpretive trail crosses the island. No facilities on the island.

Photo: [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:MoundKeyShellMound.jpg), public domain, State of Florida.