Olomouc

Olomouc was probably built on the site of a Roman fort.

An excerpt from the article 19 facts about Olomouc

It was founded during the Roman Empire as Luliomontium (Mount Julius). While not documented, archaeological excavations near the city have revealed the remains of a Roman military camp from the time of the Marcoman Wars in the late 2nd century.

In the late 7th century, the first Slavic settlement was established there.