Torrione e Rivellino, Fortified tower, city gate and ravelin in Piombino, Italy.

Torrione e Rivellino is a fortified complex in Piombino made up of a tall defensive tower and a semi-circular outer structure designed to resist cannon fire. Together these two components form an integrated defense system with thick stone walls positioned to cover different attack angles.

The tall tower dates to 1212, when Piombino was a free commune, and held the city's Porta a Terra; it was raised in the 15th century. A square platform and an outer gate bearing a plaque dated 1417 were added in the early 15th century. The semicircular ravelin, built of tuff from the Populonia quarries, is attributed to Rinaldo Orsini, husband of Caterina Appiani, though its construction details point to 1470–1504. Cosimo I de' Medici had the Guelph merlons removed between 1548 and 1557.

The tower was also called Torre di Sant'Antonio or Porta Inferi, and bells hung under its arch, rung for special occasions or to warn of danger. The Rivellino's tuff came from the same Populonia quarries that supplied the Etruscan buildings of the area.

The complex stands at the end of the old wall circuit in Piombino, where the tower and the semicircular ravelin face each other across the former moat line. The ravelin's side entrance and gun ports are best read from outside, walking around the base; the 1417 plaque sits on the antiporta of the tower.

The ravelin section uses volcanic tuff stone, the same material found in Etruscan buildings scattered across the region. This stone type connects the medieval fortress to the much older architectural heritage of the area.