Near Narlıkuyu, a road winds north for 2km to several caves – sinkholes carved out by a subterranean river and places of great mythological significance. The walk from Narlıkuyu junction to the main entrance gate is quite steep. Enterprising locals usually offer taxi services up the hill for ₺10 (one way).
The mammoth underground Chasm of Heaven (Cennet Mağarası) – 250m long, 110m wide and 70m deep – is reached by 450-odd steps to the left of the ticket booth. Right in front of the cave mouth (and at the 300th step) are the tiny but beautiful remains of the 5th-century Byzantine Chapel of the Virgin Mary, used for a short time in the 19th century as a mosque. Once inside the cave, the stairs can be very wet and slippery and there are no handrails, so wear decent shoes and walk carefully. At the furthest end of the colossal grotto is the Cave of Typhon (Tayfun Mağarası), a damp, jagged-edged, devilish theatre. Locals believe this to be a gateway to the eternal furnace, and the 1st-century AD historian Strabo mentions it in his Geography. According to legend, the cave's underground river connects with the hellish River Styx – this seems plausible when you hear the underground current thundering away below.
Back on terra firma, follow the path from the ticket office further up the hill to the Pit of Hell (Cehennem Mağarası) with its almost vertical walls that you view by stepping out onto a heart-stopping platform extending over the 130m-deep pit. This charred hole is supposedly where Zeus imprisoned the 100-headed, fire-breathing monster Typhon after defeating him in battle.