Torre di Buranaccio, Coastal defense tower in Capalbio, Italy.

Torre di Buranaccio is a coastal tower on the shore of Lake Burano in Capalbio, the southernmost along Tuscany's Tyrrhenian coast. It has three levels, a square plan on a massive battered base joined by a string course, and stone-clad walls 2 to 3 metres thick. The top carries a terrace without battlements on broad projecting corbels, with a small rectangular masonry structure at one corner.

The present fortification was built around the mid-16th century on a site that probably held a medieval structure. It served as the southernmost defensive outpost of the State of the Presidi, on the border with the Grand Duchy of Tuscany and the Papal States. Later renovations left its original appearance almost intact.

The tower served as a lookout point in a coastal warning network where guards communicated dangers to neighboring settlements through smoke and fire signals. This signaling system was essential for alerting communities to sea-based threats along the shore.

The tower stands on the shore of Lake Burano at the southern end of Capalbio's coastline, within the Burano Lake nature reserve. The sources record no staircase, interior access or opening times, so the structure should be viewed from outside; the terrain around the lake is flat and walkable.

The structure houses a water cistern in its lower section, allowing occupants to maintain supplies without leaving the safety of the fortification. This feature was essential for sustaining the garrison during extended periods of isolation or threat.