Nardò Cathedral has been since 1986 the episcopal seat of the diocese of Nardò-Gallipoli. The present cathedral probably stands on the site of a Byzantine church. In 1080, a church was built here by the conquering Normans, which was elevated to the status of a cathedral in the early 15th century.
The building has undergone a number of refurbishments. The present façade dates to 1710–1725. The interior contains both medieval frescoes and 19th-century frescoes by Cesare Maccari.
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.