The massive collection of perfectly round balls along the Gulf of Ob makes it seem giants are getting geared up for an epic snowball fight.

Each one is perfectly round and stacked neatly along the 18-kilometer (roughly 11 miles) coastline, so it's mind-blowing that the snowballs are a result of a natural phenomenon and not an art exhibit or a group of people preparing for an ambitious winter fight. But it is an entirely natural event.

According to a report from BBC, the rare phenomenon occurs when pieces of ice form, then are rolled by wind and water, collecting more and more snow, and ending up as massive snowballs.

"As a rule, first there is a primary natural phenomenon - sludge ice, slob ice," Arctic and Antarctic Research Institute press secretary Sergei Lisenkov said in Russian television. "Then comes a combination of the effects of the wind, the lay of the coastline, and the temperature and wind conditions. It can be such an original combination that it results in the formation of balls like these."

The ones in Siberia vary in size, ranging from as small as tennis balls to nearly one meter across.

The rows and rows of snowballs have delighted the local people of Siberia, particularly in the village of Nyda above the Arctic Circle, where the snowballs were first discovered less than two weeks ago.

"We have them only in one place," local resident Ekaterina Chernykh shared in a report from Siberian Times. "It's as if someone spilled them. They are all of different sizes, from tennis balls to volleyball."

She added, "We all were very surprised. Many people believed it only when saw with they own eyes. This has not happened previously. And there was not so much snow for them to form. It's so interesting."

Similar snowballs were found in Lake Michigan and the Gulf of Finland in previous years.