 Much of Mérida's architecture from the colonial period through the 18th century and 19th century is still standing in the "centro historico" of the city.From colonial times through the mid-19th century, Mérida was a walled city intended to protect the Peninsular and Criollo residents from periodic revolts by the indigenous Maya.Several of the old Spanish city gates survive, but modern Mérida has expanded well beyond the old city walls.