Cave diving in Attica and the Peloponnese
The warm, deep Lake Vouliagmeni near Athens (to -127 m, permit only) and the Devil's Well, deep freshwater springs in the mountains of Argolida and Arcadia (Sintzi to -240 m, Kefalovrysos) and sea caves along the coasts of Attica, Corinthia and Kynouria.
12 caves · down to 240 m · 4 suitable for an intro team
All 12 caves
| Site | Max depth | Type | Certification |
|---|---|---|---|
| Arcadian Village cave (Arkadiko Chorio) | 55 m | Backmount | Full cave |
| Devil's Well (Pigadi), Vouliagmeni | 45 m | Sidemount | Full cave |
| Katelanos cave | 24 m | Backmount | Intro to cave |
| Kefalovrysos (Inachos spring) | 30 m | Sidemount | Full cave |
| Keratea sea cave (Daskalio) | 42 m | Sidemount | Full cave |
| Korfos cave | 14 m | Backmount | Intro to cave |
| Krioneri undersea cave | 30 m | Backmount | Intro to cave |
| Lake Vouliagmeni | 127 m | Backmount | Full cave |
| Peristera cave (Methana) | – | Sidemount | Full cave |
| Psatha cave (George's Cave) | 31 m | Not known yet | Intro to cave |
| Sintzi | 240 m | Sidemount | Full cave |
| Tiros sea cave | 50 m | Sidemount | Full cave |
Certification requirements, configurations and trimix depths are estimates for planning. Always check them locally and dive within your training.
Practical info: rules, fills and emergency numbers
Emergencies
- 112; DAN Europe +39 06 4211 5685. The Naval Hospital of Athens (Ναυτικό Νοσοκομείο Αθηνών) has a diving and hyperbaric medicine unit; after a diving accident call 112 and DAN first.
Access and rules
- Diving law (3409/2005, amended by 4688/2020): always dive with a buddy; no diving in shipping lanes and anchorages, military exercise areas, marine protected areas, near submarine cables or where the Port Authority prohibits it. Do not raise, move or photograph antiquities; report finds and wrecks to the Port Authority. Wrecks older than 50 years and night dives only with a licensed dive centre. Dive flag on the boat; a buoy when you dive more than 50 m from the boat or without a boat. Law 4688/2020 also opened 'accessible underwater archaeological sites', accompanied dives only.
- Caves: the Ephorate of Palaeoanthropology and Speleology (Ministry of Culture; Ardittou 34b, Athens) researches and protects caves and fossil remains. Lake Vouliagmeni has been closed to general diving since 1995; cave diving is only allowed with a permit from the management company (Thermal Loutra Vouliagmenis – Tourist Enterprises SA) and under the supervision of an affiliated cave instructor. No permit rule is known for the other caves; Kefalovrysos is a drinking-water spring — check with the municipality.
Gas and fills
- Gas: no trimix or O₂ fill station is known in the region. Planet Blue in Lavrio (East Attica) is a recreational SSI centre with rental and a nitrox course; arrange helium, O₂ and sofnolime in advance. The Greek teams dive the deep caves on CCR.
Water and season
- Water: Vouliagmeni 22–29 °C (27 °C at -40 m); sea caves 13–21 °C (Korfos 13–16, Kynouria 18–19, Psatha ~21); mountain springs 10–12 °C (Sintzi, Kefalovrysos). Sintzi (~700 m) and Kefalovrysos (~750–770 m) are at altitude: set your computer for altitude diving.
Getting around
- The caves are spread over Attica and the north-eastern Peloponnese. Nafplio is central: Kefalovrysos, Sintzi, Korfos and the Kynouria coast are ~1–1.5 h drive away (estimate). For Lake Vouliagmeni, the Devil's Well and Keratea you are better off staying in southern Athens (~2 h from Nafplio, estimate).
- Boats: the sea caves at Korfos and in Kynouria are dived from a local fisherman's or skipper's boat; ask at the harbour.
Rest day
- Rest day: Lake Vouliagmeni is also a thermal bathing lake with warm water all year (paid entry); snorkelling and freediving along the walls and at the cave entrance are allowed.
Plan a cave diving trip to Attica and the Peloponnese
Enter your team, with certifications, gas and configurations, and see right away which caves fit. With driving times from your stay, fill stations and an AI instructor who thinks along.
Compiled from web research (cave pages of the Greek teams T2B, Grafas Diving and Addicted2H2O, wannadive, Wikipedia, Greek news reports 2015–2026, summaries of diving laws 3409/2005 and 4688/2020; Sept 2026). Pins from T2B, wannadive or Wikipedia (see each site); ~ = estimate. Rules change — check locally.