After the 6th century, the Circus fell into disuse and decay, and was quarried for building materials. The lower levels, ever prone to flooding, were gradually buried under waterlogged alluvial soil and accumulated debris, so that the original track is now buried 6m beneath the modern surface. In the 11th century, the Circus was "replaced by dwellings rented out by the congregation of Saint-Guy."
[47] In the 12th, a watercourse was dug there to drain the soil, and by the 1500s the area was used as a market garden;
[48] Many of the Circus' standing structures survived these changes; in 1587, two obelisks were removed from the central barrier by
Pope Sixtus V, and one of these was re-sited at the
Piazza del Popolo. Mid 19th century workings at the circus site uncovered the lower parts of a seating tier and outer portico. Since then, a series of excavations has exposed further sections of the seating, curved turn and central barrier but further exploration has been limited by the scale, depth and waterlogging of the site.
[49]
The Circus site now functions as a large park area, in the centre of the city. It is often used for concerts and meetings. The
Rome concert of Live 8 (July 2, 2005) was held there, as was the Italian
World Cup 2006 victory celebration. The English band
Genesis performed a concert before an estimated audience of 500,000 people in 2007. This was filmed and released as
When in Rome 2007.