Under the ground of the Plaza de Velarde, also known as Plaza Porticada, are the archaeological remains of a section of the medieval wall of the town built after the granting of the fuero in 1187, in the time of King Alfonso VIII of Castile. Specifically, this is the section between the gateway of Don Gutierre de Escalante and the Puerta de la Mar.
Thanks to these remains, and with the help of old maps, it is possible to understand the urban development of this part of the city, which had a central area defined by the walled outline of the town and which included the two villages and the new area that extended eastwards due to the development of the port and its surroundings. This area is now one of the most recognisable images of the city.
In addition, objects of great interest that were found during the recovery of the space are exhibited, such as ceramics from Santillana del Mar, Manises, France, coins from different periods, pipe fragments from the 16th century... and many other pieces.
The remains of the wall and other elements, such as ceramics, parts of paved streets and the structures of ancient towers, offer the visitor the possibility of travelling from the Middle Ages to the 20th century in order to understand the evolution of Santander from a medieval fishing village to the modern city that has grown up around the port.