The "Mint Tower" was originally built in the 1600s, then rebuilt in 1885. It stands in Muntplein Square, at the intersection of the Amstel River and the Singelgracht.
Amsterdam reportedly has 2500 bridges throughout the area, crossing the canals that were dug during the Middle Ages to enable easy travel throughout the city.
The Museu d'Historia de Barcelona has excavated miles of Roman ruins of the original city of Barcino, founded by the Romans more than 2000 years ago, under the streets of modern Barcelona.