Pamukkale

The white 'cotton castle' built by hot water

Pamukkale means 'cotton castle' in Turkish: the hillside is white as snow, but it isn't snow — it's stone! Hot water from underground carries dissolved limestone; as it cools, the lime turns to stone and forms terraced pools. The pools hold warm (35 °C) blue water, and you can walk in them barefoot. 2,000 years ago the Romans built the city of Hierapolis here and bathed in the healing water.

Pamukkale is a series of travertine terraces 2.7 km long and 160 m high in the Menderes valley of south-western Turkey. Seventeen hot springs (35–100 °C) carry water saturated with carbon dioxide and dissolved calcium bicarbonate; at the surface it loses CO₂ and calcium carbonate precipitates — 1 mm a year; the terraces formed over 400,000 years. The calcite is chalk-white, the pools turquoise. Hierapolis (2nd century BC, Kingdom of Pergamon, later Rome) was a spa city: a 12,000-seat theatre, a necropolis of 1,200 tombs, the 'Plutonion' — a CO₂-venting cave (the 'gate to hell', where birds died). Cleopatra's Pool lets you swim among ancient columns. UNESCO (natural + cultural) since 1988. In the 1990s hotels drew off the water and the terraces darkened — the hotels were demolished, water flow is now rotated, and shoes are banned.

Fun facts

• Pamukkale's terraces grow 1 mm a year — they took 400,000 years to form.
• The Romans left a 12,000-seat theatre and a 'gate to hell' cave here.
• You may only walk the terraces barefoot — shoes damage the stone.