The O Castro site is Vigo’s archaeological site par excellence: this was the origin of what is now the largest city in Galicia, between the second century BC and the third century AD. When you step on the stones of this museum site, the O Castro de Vigo. A Orixe da cidade, you’ll discover where the first inhabitants of Vigo lived.
The Castro is a 1 mile² archaeological site that includes the reconstruction of three castreño buildings pertaining to one of the largest and most evolved towns in Galicia. This small part of the Vigo oppidum shows us how people lived in castros 2,000 years ago.
http://www.turismodevigo.org/en/o-castro-site