Glaronissia
Milos · Greece
Glaronissia is a tiny uninhabited islet cluster off Milos's north coast composed entirely of hexagonal basalt columns — a geological spectacle that continues vertically beneath the surface, with columns dropping into clear blue water to 30 metres. The walls between the columns are carpeted in coralline algae and encrusting sponges, and large grouper patrol the base of the structure with territorial authority. The site feels genuinely prehistoric, and the contrast between the dark basalt and the azure Aegean water is one of Greece's most memorable underwater vistas.
Conditions
Depth
5 to 30 m
Open water and up
Current
Usually still
Can pick up on the edge
Visibility
20 to 30 m
Clearest in the calm season
Water
14 to 27°C
3mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 14 | 14 | 14 | 16 | 18 | 22 | 24 | 25 | 24 | 22 | 18 | 15 |
| Vis (m) | 15 | 15 | 15 | 18 | 20 | 20 | 20 | 20 | 20 | 18 | 15 | 15 |
| Current | Gentle | Moderate | Gentle | Still | Still | Still | Still | Still | Still | Gentle | Gentle | Gentle |
Your chances of seeing each animal
Ornate Wrasse
Last confirmed Jun 17, 2026 · 15 records
Very likely
Most dives
Hooded Crow
Last confirmed Jun 20, 2026 · 27 records
Very likely
Most dives
Striped Red Mullet
Last confirmed Jun 19, 2026 · 8 records
Very likely
Most dives
Milos Wall Lizard
Last confirmed Jun 23, 2026 · 38 records
Likely
About 6 in 10 dives
Levantine Viper
Last confirmed Jun 17, 2026 · 32 records
Likely
About 6 in 10 dives
Dusky Grouper
Last confirmed Aug 10, 2025 · 2 records
Likely
About 6 in 10 dives
Cat Snake
Last confirmed Jun 17, 2026 · 13 records
Likely
About 6 in 10 dives
White Sea Bream
Last confirmed Jun 9, 2026 · 10 records
Sometimes
About 1 in 3 dives
Gear