
Castellot de Mas Mateu is a medieval fortress located in Montmell, in the Baix Penedès region of Tarragona province, and is declared a National Heritage Interest Property. The structure features a ruined square tower measuring 10 meters at its base with approximately 9 meters of height preserved, constructed from large, well-fitted stone blocks that demonstrate medieval masonry craftsmanship. This castle represents an important example of 11th-century defensive architecture in the Tarragona region and remains one of several significant medieval fortifications that once protected the territory.