What to see in Tarragona? The Roman Amphitheatre is one of the chief highlights of a trip to Tarragona. It is set beside the sea, and this fact makes it impressive. It is just an hour of train ride at the south of Barcelona. This Amphitheatre was built in the 2nd Century AD — and it is a stunning legacy of a time when Tarragona, or Tarraco as it was called at that time, was one of the capitals of Hispania, which was ruled by the Romans.