🔢 Blog · 4 min read

10 Green Canyon Facts You Can Actually Verify

Quick answer

Ten facts that survive checking — the dam, the drowned spring, the colour physics and why the canyon is boat-only.

Most writing about the Green Canyon runs on adjectives. This page runs on facts — ten of them, each one checkable, covering the dam that made the lake, the river that fills it, the spring it drowned and the physics behind that improbable colour. We operate boats here daily in season; this is the short version of what we tell guests who ask good questions.

The ten facts

Numbered for easy retelling — quote us anywhere.

  • 1. The Oymapınar Dam that created the lake is a double-curvature concrete arch about 185 metres tall, built between 1977 and 1984.
  • 2. Its four turbines sit in an underground powerhouse — you can cruise the whole lake and never see the machinery.
  • 3. The reservoir holds roughly 300 million cubic metres of water spread over about 4.7 square kilometres.
  • 4. It filled in 1984 and is billed as Turkey’s largest canyon reservoir.
  • 5. The river behind it all is the Manavgat — 93 kilometres long, known in antiquity as the Melas — fed by giant karst springs: cold, clear and remarkably steady all year.
  • 6. One of those springs, Dumanlı, was once proposed in the scientific literature as the world’s largest karst spring.
  • 7. Dumanlı now lies drowned about 120 metres below the surface near the dam — and most likely still flowing.
  • 8. Before the lake, Dumanlı fed ancient Side’s aqueduct; around forty arches of it still stand near the dam.
  • 9. The emerald colour is physics, not editing: limestone-filtered spring minerals under direct sunlight, strongest around midday.
  • 10. There is no shore promenade — the walls rise straight from the water, so the canyon is experienced only by boat.

How to check them from a boat deck

Every fact above is visible, or at least felt, from the water. Our classic boat tour spends about four and a half hours on the lake, with a freshly prepared lunch on board and several unhurried swim stops — the cold-spring fact announces itself the moment you jump. The catamaran covers the same scenery in about two and a half hours, with one swim stop and a spacious open deck. Nothing is paid online: you book, we confirm the same day, and you pay on the tour day, with free cancellation up to 24 hours before. Current rates are on our prices page, and our getting-there guide covers pickup from Side, Manavgat, Alanya, Belek and Antalya.

Frequently asked questions

How deep is the Green Canyon? +
Genuinely deep — near the dam the drowned Dumanlı spring lies about 120 metres below the surface, which gives you the scale. Depth varies along the lake; swimming happens only at designated stops announced by the crew, from the boat, with vests aboard including child sizes.
When was the Green Canyon created? +
The limestone canyon is ancient; the lake is not. The Oymapınar Dam went up between 1977 and 1984, and the reservoir filled in 1984 — everything emerald you cruise on is younger than many of our guests.