A pre-Columbian site, Cajamarquilla is a crumbling adobe city that was built up by the Wari culture (AD 700–1100) on the site of a settlement originally developed by the Lima culture. Still undergoing renovation, a visit may be arranged by calling the Ministry of Culture ahead of time.
A road to the left from Lima at about Km 10 (18km from Central Lima) goes to the Cajamarquilla zinc refinery, almost 5km from the highway. The ruins are located about halfway along the refinery road; you take a turn to the right along a short road. There are signs, but ask the locals for the zona arqueológica if you have trouble finding them.