The Castillo Palacio de Marcilla is a Gothic-style castle built in the 15th century by Mosén Pierres de Peralta. At first it had a defensive character but when the Marquisate of Falces was instituted it became the residential palace of the Marquises. The gateway to the castle, which houses the drawbridge under which the moat runs, is next to what is considered to be the Homage Tower, one of the four towers that make up the corners of the castle. Inside the fortress there was a large parade ground around which the rooms and rooms were distributed. The palace chapel preserves its 16th century paintings.
Acquired by the Government of Navarra in 1976 and thoroughly restored in the 2008-2012 period, it currently houses the town hall and other municipal bodies.
Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.