Not a math post, but cool nonetheless:
In polar and other cold regions there are ice, snow and water formations that are unusual, unique, and some of them so beautiful to breathtaking. Most of these wonders of nature can be visited only by scientists and rare adventurers who are ready for significant physical and financial exertions. Because of their volatility and locations, these formations can be seen only at certain periods of the year.
Thanks to Bole982 for this submission!