
Niagara Falls is a popular summer attraction, but it can be a spectacular scene in winter as well. An unprecedented cold front in February 2015 froze parts of the falls, drawing tourists to document the rare event. The minus 22-degree weather didn't stop iReporter Spencer Wyllie from capturing this photo.

Most of the icy buildup was on the American and Bridal Veil Falls (as opposed to adjacent Horseshoe Falls), Wyllie said.

Professional photographer and iReporter Dave Perry also journeyed to see the frozen wonderland. He said it was "so cold I wondered why I was taking photos here but the scene makes it worth the trek."

Perry spotted some unusual frozen formations near the falls.

The Burlington, Ontario, resident walked along the edge of the falls, where he saw the American side glistening with ice.

Only after taking a series of photographs did Perry realize the falls were frozen. "It didn't strike me at first when I took this shot," he said. "I thought it looked like teeth, like a monster's smile."

The ice formations along the falls are mostly formed by mist. Perry and hundreds of tourists from America and Canada made their way to see the frozen scene.

The National Weather Service said extremely cold Arctic air allows for expansion of ice -- sometimes called an "ice bridge" -- across the river.