Caves are travel's most reliable surprise: the temperature is always interesting, the light is always strange, and the rocks have been working on the room for longer than humans have had countries. Find walk-through showcaves, ice caves and serious caving expeditions below.
Ceilings drop without warning. Even guided tours hand them out for a reason.
A head-torch plus a backup. Phones run flat fast in cold air.
Even tropical caves sit at 10β15Β°C year-round. Layer up.
Touching speleothems coats them in oil that stops them growing. Hands off everything.