The stately Pantheon is one of the world's most inspiring architectural designs; almost two thousand years after it was built, the Pantheon's dome is still the world's largest unreinforced concrete dome. Built as a temple to the Roman gods by Hadrian in 120 AD, its perfectly proportioned floating dome rests seductively on sturdy marble columns. The only light source is the central oculus, which was used by the Romans to measure time (with the aid of a sundial) and the dates of equinoxes and solstices. The sunlight pouring through the oculus and illuminating the floor in the otherwise dark church is quite a sight. The south transept houses the Carafa Chapel and the tomb of Fra Angelico rests under the left side of the altar. The Pantheon is still an active place of worship and Christian services are conducted regularly. Visitors should show respect and keep their voices down; this is not difficult as the interior inspires awe and humility which is perhaps why the atmosphere is almost always peaceful and quiet despite the crowds of people that visit. Photography is allowed and there are audio guides available for hire. One of the most iconic buildings in the world and certainly among Rome's most famous attractions, the Pantheon is a must-see which seldom leaves visitors unaffected.

Address: Piazza della Rotonda

Transport: Buses 46, 62, 64, 170 and 492 stop at Largo di Torre near the Pantheon; or take the metro to Fontana del Tritone

Opening times: Open Monday to Saturday, from 8:30am to 7:30pm; on Sundays from about 9am to 6pm. Closed New Year's Day, 1 May and Christmas Day.

Admission: Free