Sinkholes!

What it is sinkholes? 

Is it type of holes in kitchen sink?

Or what?

Sinkholes are considered a type of land subsidence, because they involve a vertical  downward movement of the land surface. There are three types of sinkholes, each of which forms in a different way. Collapse sinkholes are the most hazardous to humans because of how suddenly they can form. Sinkholes aren’t uncommon, as about 10 percent of the world’s landscape is composed of karst regions.

Want to know how it happens? Move and put some energy on your mouse here!