Torre Truglia, Coastal defense tower in Sperlonga, Italy.

Torre Truglia is a stone tower built on a rocky promontory that juts into the Tyrrhenian Sea, at the edge of Sperlonga's old town. Its thick walls follow a Renaissance military design meant to resist attacks from both the sea and the land.

The tower was erected in 1532 on the remains of a Roman watchtower at the tip of the promontory above Sperlonga. Pirates under the corsair Barbarossa destroyed it, and it was rebuilt in 1611, only to be destroyed again by the Turks in 1623. From 1870 to 1969 it housed the Guardia di Finanza.

The tower's name has no documented family origin in the sources; what is recorded is its later use. From 1870 to 1969 it housed the Guardia di Finanza, Italy's finance police, before becoming the seat of the marine environment education centre of the Riviera d'Ulisse regional natural park.

The tower sits about a ten-minute walk from Sperlonga's town center, with paths leading from both the upper town and the beach below. The approach crosses rocky ground that can get slippery after rain, so firm shoes are a good idea.

Inside the tower today is a marine education center focused on the plants and animals of the Mediterranean Sea. On calm days, it is possible to spot dolphins from the promontory, moving through the water just below the rocky walls.