The castle lies inside the square perimetral walls, surrounded by a moat; the walls are mostly well preserved together with the two corner towers and the imposing southern entrance. It presents double side embrasures. The Northern part hosts the Rocchetta that was supposed to face the attacks coming from the river Po. It was transformed into a coutryside mansion in the past century, and it is characterized by wide vaulted halls and decorations of the time.The actual castle lies in the background in the northern side and has an angular tower and a huge donjon located in an internal position and developing around the inner ward . It preserves part of the originary crenellation and acute angle windows .Inside there are several wide halls, some vaulted and some with a caisson ceiling, small parlours, bedrooms, all furnished with ancient furniture. The fortified borough probably already existed in 1216, when Piacenza and Milan armies gathered before attacking Pavia fortresses. Sarmato castle was an important outpost built by Piacenza (guelf town) to defend Tidone valley from enemy incursions.
Sarmato castle is still inhabited by the Zanardi Landi counts and is open for visits to the garden, the façades, frescoed rooms and furnished rooms, the archive, the large ballroom, bedrooms and the so called “Sala dei filosofi” (philosophers’ room) attributed to Bonifacio Bembo.