On Monday, the temperature at Niagara Falls dropped to 13 degrees below zero. The drop in temperature left parts of Niagara Falls frozen, while the surrounding area was covered in snow and mist. The transformation brought more tourists to the area, mostly photographers who want to photograph the majestic waterfall in its frozen state.

According to CNN, while the falls may look frozen on the surface, water is still flowing under the ice. The only time that the water flow in Niagara Falls stopped completely was back in 1848 due to an ice jam upriver. However, 1912 saw one of the coldest recorded winters in US history according to data compiled by the United States Weather Bureau, established in 1870. Temperatures dropped so low due to an Arctic cold wave that the falls was dense enough for people to walk across it safely. The cold wave started in December 1911, and continued through February of 1912.

The Niagra Falls completely frozen in 1911. pic.twitter.com/46u1hl6QBS

— Geoff’s-Vision (@Visiongeo) March 4, 2014

The Niagra Falls partially frozen in 2014 while illumintaed by multi-coloured lights. pic.twitter.com/vc0bsd8ULq

— Geoff’s-Vision (@Visiongeo) March 4, 2014

Photographer Christine Hess was one of the tourists who flocked to Niagara Falls to document its winter transformation. “There’s something about shooting the falls that leaves me mesmerized. I could walk down there for hours with my camera and never tire of the scenery. I’m in my own little world down there,” Hess said. And while it is definitely an incredible sight, it is not uncommon for parts of Niagara Falls to freeze during winter. In fact, last January, a photograph of the frozen falls became viral.

It’s so cold out that Niagra Falls has partially frozen over http://t.co/o5xzo0cNyZ pic.twitter.com/WChdSFrzo3

— Business Insider (@businessinsider) February 18, 2015

#cool #pic Niagra Falls, partially frozen from the extreme cold. (Photo credit twitter @christine_chess): … http://t.co/d2CRVoooAX

— Marijuana 420 (@MarijuanaFour20) February 20, 2015

GALLERY: Stunning @AP images show a frozen Niagra Falls http://t.co/ZFQV2soIun pic.twitter.com/VBQu2f9ogW

— Sun Herald (@sunherald) February 19, 2015

Michelle Blackley, communications and community relations for the falls told USA Today, “The attention the falls is receiving is bringing a crowd to view them in their majestic, winter splendor.”

According to the Great Lakes Environmental Research Laboratory, the lakes are now more than 85% iced over. The report also says that Lake Erie is already 98% frozen. And while 85% is a little high, it’s actually quite common in the Great Lakes. In fact, the record for the most ice coverage in the Great Lakes is 94.7% and it happened back in 1979. Last year’s peak was 92.5%. The National Weather Service says that extremely cold arctic air might expand the ice coverage in the coming days.