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Lake Marathon

A mountain reservoir held back by a dam faced in Pentelic marble, often called the only one of its kind in the world.

Updated 14 October 2026

Lake Marathon

AI illustration

WhereAttica
Nearest cityMarathon
Best seasonOctober to May
Time to allowTwo to three hours
Getting thereNortheastern Attica about 40 km from Athens; car
EntryFree to view from the dam road

Built between 1926 and 1929 to give Athens a reliable water supply, the dam closed the valley of the Charadros and created a lake of some 2.5 square kilometres in the hills below Mount Parnitha. Its designers faced the entire downstream wall in Pentelic marble, the same quarry that supplied the Parthenon, and it is often called the only marble-clad dam in the world; a small copy of the Athenian Treasury at Delphi stands at the foot of the dam as a monument to the engineers. The lake supplied all of the city's water for decades and remains part of the network, so swimming and boating are forbidden and the shoreline is fenced in most places. The road along the top of the dam is open, and pine-covered slopes with picnic spots run around the eastern side.

The landscape

  • The marble dam - the white downstream face and its crest walkway.
  • The treasury replica - a scaled copy of a Delphi building at the foot of the dam.
  • The reservoir - still water below wooded hills, best in the morning.
  • The pine slopes - shaded viewpoints along the approach roads.

When to go

Autumn to spring, when the water is high and the hills green; late summer drops the level and exposes bare shoreline. Mornings are calmest for reflections.

Practical notes

This is working infrastructure, not a leisure lake: no swimming, no boats, fences along most of the water, and no visitor facilities. The dam itself is the sight, and half an hour covers it unless you walk the surrounding tracks.

Nearby

Schinias beach and the Marathon plain lie east; Mount Parnitha rises to the west.

Key facts

Local nameΛίμνη Μαραθώνα (Greek)
Area2.5 km² (0.9 sq mi)
Location38.1686° N, 23.9000° E · map

Source: Wikidata, item Q1166181, read on 18 October 2026.

What to pack for Lake Marathon

Chosen from what this place is for. Tap a kit for the full checklist.

  • Broken-in walking shoes or boots - Grip and ankle support matter more than looks; never hike in brand-new boots. Find on Amazon
  • Reef-safe sunscreen - High SPF that will not bleach the coral you are swimming over. Find on Amazon
  • Layers + a waterproof shell - Mountain weather turns fast; a packable rain jacket saves the day. Find on Amazon
  • Quick-dry towel - A microfibre towel packs small and dries in minutes. Find on Amazon

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Opening times, ticket prices and seasonal closures change - check the official source before you go: official site.

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