In case you are a frequent traveler and like vacationing with your family or friends, you sure are supposed to know about the place you are about to travel. Here is a collection of articles which will help you find helpful information like modes of travel, best season to visit, etc about these places.
10 Massive Holes In The Earth's Crust
Where: Imotski, Croatia

Crveno Jezero is the third largest sinkhole in the world. The sinkhole is named after the reddish-brown color of the surrounding cliffs, coloured by iron oxides.