Castell de Queralt, Medieval castle in Bellprat, Spain.

Castell de Queralt is a ruined fortress on a rocky crest at the western end of the Serra de Queralt. Its residential block, of Gothic workmanship, has a rectangular plan with a north facade showing a ground floor, an upper floor and a terrace, with two arrow slits and two windows. Inside, a pointed arch stands out; the outer walls are rough, while the inner faces use well-cut ashlars. Near the northwest corner is a channel of hollowed sandstone blocks.

The castle's existence is indirectly traced to Count Guifrè's repopulation of the County of Osona (880–897), when Queralt marked its westernmost limit. In 976 Count Borrell II and his wife Ledgarda sold it to Guitard, Viscount of Barcelona. From the 11th century it passed to the Gurb-Queralt lineage, and in 1212 Arnau de Timor bought it from Berenguer III de Gurb. In 1842 the Count of Santa Coloma sold the ruined castle to banker Josep Safont i Lluch.

The name Queralt appears as a surname with Guillem Bernat de Queralt, who died in 1084. The castle passed to the Safont family in 1842, when the Count of Santa Coloma sold the ruined site to the Barcelona merchant and banker Josep Safont i Lluch. The chapel of Sant Miquel, documented in 1088, was given to Santa Maria de Solsona.

The site is accessible via local roads leading to Bellprat, with coordinates marking its exact location for navigation. The elevated position offers views across the surrounding landscape but requires some climbing to explore the structures.

The ruined residential block preserves a stone channel near its northwest corner, built from hollowed rectangular sandstone blocks, beside traces of a small rectangular structure thought to be a cistern. The 1842 sale document records that the castle had housed the peasants farming the surrounding land, and plaster partitions and other remains of these occupants can still be seen.