The second largest in Hungary, this 19km-long cave discovered in 1904 is noted for both its stalactites and its bats. Be advised that the 500m route involves climbing about 120 steps and a ladder, so it may not be suitable for the elderly or young children. The temperature is a constant 8°C so wear a jacket or jumper. Tours lasting 45 minutes depart hourly from 10.15am to 4.15pm.