Around 500m west of the main entrance to the Caves of Heaven and Hell is Asthma Cave (Astim Mağarası), which supposedly relieves sufferers of the affliction. It's worth the extra ₺6 to explore these other-worldly grottoes, with their staggering limestone formations. The average temperature is 14° C and humidity ranges from 85% to 98%, depending on the season. There's a huge cafe-restaurant here, as well as a shop selling souvenirs and provisions.