Frasassi Caves

Speleologists broke into the system in September 1971 and found the Abisso Ancona, a chamber about two hundred metres long and a hundred and eighty high, with a volume large enough to contain Milan cathedral. The caves were formed by sulphuric acid rising from below rather than by rainwater dissolving from above, which produces different shapes and left gypsum deposits. The tourist route covers around one and a half kilometres of walkway past formations named the Candles, the Giants and a frozen waterfall of flowstone. Longer speleological routes with overalls and helmets go into undeveloped passages. The temperature stays around fourteen degrees.

What you actually see

• The Abisso Ancona - a chamber 180 metres high, found in 1971.
• The acid-formed shapes - passages dissolved from below, not by rainwater.
• The named formations - the Candles, the Giants and the flowstone falls.
• The adventure routes - undeveloped passages walked in overalls and helmets.

When to go

Year-round; the caves hold a constant fourteen degrees, so a jacket is needed even in August. Tours are timed and busiest on summer weekends and holidays.

Honest expectations

Entry is only on a fixed guided tour on a set route, with no wandering. Photography rules vary and have been restricted. The walkway has steps and is damp.

Nearby

The Tempio del Valadier is in the same gorge; Genga village is close.