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:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.