Just kidding, the picture shows it a bit more dangerous than it really was, but tricky it was anyway !
Nevertheless, when you go hiking in the Biokovo area (a must it is, especially during winter), the chance you discover a hole, a pit, a cave is pretty big.
But DON'T put yourself in danger, as all those karst phenomena s are both beautiful AND dangerous.
And on top of that, it's STRICTLY FORBIDDEN to cave without permission.
If interested, see these this website, highly interesting and beautiful:
When there, click on "English" and be amazed about the pictures shown and the details written.
Croatia is amazingly rich in natural sense, with so much natural beauty in every aspect, you'll have to plan a visit, a holiday, a lifetime to discover it all, and still there is more.
(Reason for me to live here nowadays !)
Should you be more interested in a lazy beach holiday, Roman history, flowers, wildlife, rafting, canyoning, hiking, biking or good food and basic values, lucky you, as Dalmatia has it all :-)
Should you need help, contact my good friend Robert, as he can help you make your stay a special experience from beginning to end.
In the mean time he and I will continue to discover a lot more, merely for our own pleasure, but also yours till you decide to do so yourself !
Those shoe people already said it very simple and clear:
JUST DO IT