Not far from the entrance to the Lipu Oasis is the Church of the Holy Spirit, in the basement of which is hidden an underground mausoleum: only the lower, circular level is visible, with a pillar in the centre and five niches around it, all surmounted by an arch. This sepulchre, illuminated by beams of light coming from slits in the shape of wolf jaws, dates back to the 3rd-4th century AD and was built in brick: it is assumed that it also had an upper floor, being a mausoleum similar to those of Tor Schiavo and Romulus along the Appian Way.