Castro de São Lourenço is an archaeological site in the parish of Vila Chã, municipality of Esposende in Portugal. An archaeological team under the leadership of Professor Carlos Alberto Brochado de Almeida has been excavating the area since 1985. The team divided the site into sectors based on the finds belonging to different occupation periods.
The sectors are coded as A, C, CV, D, E, N, M1, M2, and T. Sector C refers to the access route to the chapel, inhabited between the 3rd and 2nd century BC. The circular dwelling places in this sector feature white or yellow plastered walls and conical thatched roofs. Each house has a hearth at the center, next to a pole supporting the roof. Later, the clay tiles began to replace the thatched roofs due to Romanization.
The team reconstructed some of the houses in sector CV, dating from a period of change between the 1st century BC and the 1st century AD. Sector D features the Castro and a Roman wall. Meanwhile, the sectors E and A were the areas on either side of a staircase leading to the current chapel of São Lourenço. These places were no longer in use during the Roman period when the inhabitants settled on the top of the mountain to better observe the coastal region in case of an invasion.
Most of the excavations took place in sector T where ceramics of different periods and cultural contexts were found, including Greek ceramics from the 4th century BC. There were also several silver coins dating from the periods of Augustus and Tiberius. Sectors M1 and M2 located in the middle of the slope show similar findings as sector T.