Several prehistoric settlements and remains of a Roman road station have been discovered in Welschdörfli, the old town district in Chur. You can visit the excavations and discoveries on the Ackermann grounds on Seilerbahnweg.
The protective structures covering the archaeological sites from the Roman era were built in 1986 according to designs by local architect Peter Zumthor. They do not only protect the finds, they are also a museum and architectural masterpiece. The weighty building with its delicate rilled outer surface is reminiscent of the original Roman edifices.
You can get the key to the protective structures from the Chur Tourism information centre at the station.
References: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.