A chapel at the bottom
A fifth-century chapel guards the mouth of a cave where an unseen underground river roars.
Nabmj — CC BY-SA 4.0 · Nabmj — CC BY-SA 4.0 · Dosseman — CC BY-SA 4.0 · Cobija — CC BY-SA 4.0
An hour west of Mersin, two enormous holes open in the limestone plateau, and the names people gave them long ago, Heaven and Hell, are not decoration. Cennet is a broad collapse pit some 250 metres across and about 70 metres deep, its floor green and shaded; at the bottom, a small fifth-century chapel stands at the mouth of a deeper cave where an underground river roars unseen, the same water that is said to surface cold in Narlıkuyu bay below. Cehennem is narrower and far deeper: 128 metres of rock with walls that lean inwards, so nobody goes down at all, and the ancient Greeks said Zeus had chained the monster Typhon inside. The contrast is real. One invites you in; the other pushes you back. Getting to the floor of Cennet means around 450 stone steps, and the climb back used to be the part families and older visitors dreaded. Since 2020 a panoramic lift carries you up, though in summer the queue for it grows long, so budget time. Past the chapel the path into the cave turns wet, dim and slippery: trainers are a requirement, not a preference, and a pushchair is useless here, so leave it in the car and carry the little one. Over Cehennem, a glass-floored viewing platform added in 2021 hangs out above the abyss, and that is where every photograph of the day gets taken. Six hundred metres away is the small Astım (Asthma) Cave, all stalactites and damp air that Turks have long believed eases the lungs; on the ministry's official tariff it is a separate site with its own ticket, also about 12 EUR, so ask at the gate whether a combined ticket is on offer. Cennet and Cehennem itself is a Ministry of Culture site: foreign adults pay about 12 EUR, and it opens daily from 08:00 to 21:00 in the summer season, closing earlier in winter, usually around five. In August the surface heat is heavy, but the floor of Cennet runs several degrees cooler, so descend early or in the last hour before sunset. From Mersin the drive is the easy way: the D400 coast road west towards Silifke for roughly 70 km, then a signed turn at Narlıkuyu that climbs about two kilometres to the car park. Without a car, take a Silifke bus from Mersin, get off at the Narlıkuyu junction and grab a short taxi up. Make it a full day: after the sinkholes, drop down to Narlıkuyu for grilled fish on the bay and the Roman mosaic of the Three Graces in its tiny museum.
A fifth-century chapel guards the mouth of a cave where an unseen underground river roars.
A platform added in 2021 hangs straight out over a 128-metre drop.
Since 2020 a lift brings you back up from Cennet's floor, which makes the visit workable for older relatives.
Narlıkuyu Mahallesi, Hasanaliler Mevkii, Silifke
Yes, with a caveat: the lift removes the climb, but the descent is still a long staircase and the cave passage to the chapel is slippery, dark and hopeless for a pushchair. A grandmother who cannot manage stairs can still enjoy the glass terrace over Cehennem and the view of Cennet from the rim, and those two alone justify the drive.
Go down. The caves take two hours at most, and Narlıkuyu is minutes away with fish restaurants on the bay and a famous Roman mosaic; back along the same road towards Mersin, Kızkalesi castle sits out in the sea. A full day out of Mersin is well spent.