Pergamon Altar - Pergamon Museum in Berlin

The Pergamon Altar is a monumental construction built during the reign of King Eumenes II in the first half of the 2nd century BC on one of the terraces of the acropolis of the ancient city of Pergamon in Asia Minor. On this reconstruction on display in the Pergamon Museum (Berlin), you can climb the stairs and admire the decoration.

Alcántara Bridge

The Alcántara Bridge is a Roman stone arch bridge built over the Tagus River at Alcántara, Spain between 104 and 106 CE by an order of the Roman Emperor Trajan in 98. On the middle of the bridge there's a triumphal arch, and along one of the exits there's a nearly completely preserved roman temple.