Cecilia Metella's Mausoleum and the Castrum Caetani constitute an archaeological continuum, located in Via Appia Antica. The construction of the Mausoleum was intended to celebrate the importance of family more than the dedicatee, and is dated to the second half of the first century BC. The original monument was made by circular building that still stands, installed on a foundation square of cement work. The drum that contained the burial chamber was entirely covered with travertine blocks and ended in a small dome. Top it ran a frieze of floral swags alternating bucrania. The Monument and surrounding grounds were already in possession of the Church, but the final fortification building and its integration into a real fortified Castle, took place at the end of the thirteenth century by the Caetani, the powerful family of Boniface VIII. In the enclosure they were included other towers, a village and a large church dedicated to St. Nicholas of Bari, of which remains the only standing wall structure.