Hranice Abyss
Hranice Abyss · Czech Republic
Hranice Abyss (Czech: Hranická propast) is the deepest flooded pit cave in the world. It is a karst sinkhole near the town of Hranice, Czech Republic.
Conditions
Depth
10 to 30 m
Open water and up
Current
Can be moderate
Can pick up on the edge
Visibility
10 to 20 m
Clearest in the calm season
Water
12 to 24°C
5mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 12 | 12 | 12 | 12 | 12 | 20 | 20 | 20 | 20 | 12 | 12 | 12 |
| Vis (m) | 5 | 5 | 5 | 5 | 5 | 10 | 10 | 10 | 10 | 5 | 5 | 5 |
| Current | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
Your chances of seeing each animal
Sand Lizard
Last confirmed May 19, 2026 · 6 records
Likely
About 6 in 10 dives
Smooth Snake
Last confirmed May 2, 2026 · 10 records
Likely
About 6 in 10 dives
grass snake
Last confirmed Jun 26, 2026 · 18 records
Likely
About 6 in 10 dives
Common Rough Woodlouse
Last confirmed Jun 4, 2026 · 5 records
Sometimes
About 1 in 3 dives
White-lipped Snail
Last confirmed Jun 11, 2026 · 5 records
Sometimes
About 1 in 3 dives
Roman Snail
Last confirmed Aug 7, 2025 · 6 records
Sometimes
About 1 in 3 dives
European Crayfish
Last confirmed Sep 12, 2025 · 2 records
Rare
Now and then
Ash-black Slug
Last confirmed May 8, 2026 · 2 records
Rare
Now and then
Gear