Torre del Riu, Historicist castle in Alp, Spain.

Torre del Riu is a castle in Alp built with historicist design that references earlier architectural periods while employing 19th-century construction methods. Its exterior and interior spaces combine classical proportions with elements inspired by fortified structures.

The building began as a defensive tower, to which a Romanesque chapel was added in the 13th century. In 1666 the Barcelona nobleman Francesc Pasqual i de Cadell bought it for 5,000 lliures. Around 1895 Josep Nicolau d'Olzina i Ferret had master builder Calixte Freixa rebuild it as a French-style castle, and the old chapel was replaced by a new one inaugurated in 1901.

The tower's name references its position near a river, reflecting regional naming traditions and local geography. Its design shows how 19th-century builders looked back to earlier architectural forms valued in Catalonia.

The castle is situated in Alp and accessible via regional roads and transportation routes through the area. As a protected cultural monument, visitors should check ahead for any visiting guidelines or restrictions on access.

In 1895 Josep Nicolau d'Olzina made a wager with two relatives over who could turn his estate into the finest medieval-style castle; he chose Torre del Riu, while the rivals picked Can Bori in Samalús and Mas Saleta in Sant Hilari Sacalm. The marquès de Monsolís won.