Castell d'Amposta, Gothic castle in Amposta, Spain

Castell d'Amposta is a medieval fortress situated on the banks of the Ebro River, featuring stone walls, arches, and the remains of the Sant Joan tower. The structure displays characteristic Gothic elements in its construction and defensive layout.

The castle is first documented in 1097, when Count Ramon Berenguer III granted the Amposta estate to Count Artal of Pallars to build a castle there. In 1150 Ramon Berenguer IV ceded it to the Order of Saint John of Jerusalem, creating the Castellania d'Amposta. In 1280 Peter the Great exchanged it with the Hospitallers for Onda and Gallur, and the castle was remodelled with new towers and a courtyard.

The castle's name survives in the title Castellania d'Amposta, adopted by the Hospitaller priory after the 1150 donation. The site is now an archaeological zone, and the medieval past is read through its excavated moats, wall stubs and the Gothic blind arch facing the river.

The castle site lies within Amposta's urban core, where the Ebro forms a rocky outcrop. The first moat followed today's canal and Carrer del Fossat, ending near the pillar of the hanging bridge; the second, cut 6 m deep and 11 m wide into conglomerate rock, keeps a 1.40 m walkway along its scarp. Look for the six semi-buried 14th–15th-century rooms beside the entrance.

Archaeological digs have uncovered ancient Iberian grain silos dating from before the castle was built. These finds reveal that the area was already settled long before the medieval period and highlight the deep history of the location.