The Hypogeum (from the Greek, meaning 'underground') is a subterranean necropolis, discovered during building work in 1902. To visit is to step into a mysterious and silent world. Its halls, chambers and passages, immaculately hewn out of the rock, cover some 500 sq metres; it is thought to date from around 3600 to 3000 BC, and an estimated 7000 bodies may have been interred here.
At the time of research the site was due to close from September 2015 until April 2016 for maintenance; check locally or online to verify it has reopened.
The ancient workers mimicked built masonery in carving out these underground chambers, and exploited the rock's natural weaknesses and strengths to carve out the spaces by hand and create a safe underground structure. Carbon dioxide exhaled by visiting tourists did serious damage to the delicate limestone walls of the burial chambers, and it was closed to the public for 10 years up to mid-2000. It has been restored with Unesco funding, and its microclimate is now strictly controlled. For this reason, when it is open, the maximum number of visitors to the site is limited (10 per tour).
Pre-booking is essential (try to book around two months before your visit). As well as online, tickets are available in person from the Hypogeum and the National Museum of Archaeology; a few are available on the day, but it's better not to chance it.
