If you visit a karstic region where there are many caves (carbonate rock), you have seen many karstic phenomena (springs, caves, etc).
Every one can join the group named "Caves and karstic springs of the world".
Group rules and description
The goal is to show many caves spreading around the world, not to collect the same pictures of same caves or places. Every picture must be geolocated.
I have to specify "karstic springs". The most important springs are often karstic. The drainage into limestones massifs is organised in conduits into a hierarchy. It's the reason why their flow is strong and variable. Of course, I will have to erase a few pictures off-topic.