The Shrinking Mill of Port Colborne, in Ontario, Canada, is an intriguing optical illusion that makes a giant grain elevator shrink the closer you get to it.

Usually, things tend to appear smaller in the distance and grow in size the closer you get to them, but that rule does not apply to the grain elevator located in Port Colborne’s Sugarloaf Marina. As motorists turn left onto Lakeshore Road west from Cement Road, they have their view filled by this massive concrete building in the distance. It’s so big it literally fills the horizon, but as you drive forward, instead of getting even bigger, it starts to shrink, and by the time you make the left-hand bend, it’s just an average industrial building in the distance. The mind-bending optical illusion has such a strong effect that nine out of ten people who see it for the first time drive back to get another look.

“As much as we take it for granted, when people see it, they’re just in awe,” former Port Colborne Mayor Vance Badawey told The Welland Tribune. “They turn off of Cement Road, slow almost to a stop to look at it, and then, 9 times out of 10, you see them drive by again a few minutes later.”

So what causes the Shrinking Mill illusion? Well, apparently, it’s a variety of factors. Some believe it is the result of changing perspectives as you drive by the grain elevator. As you turn off of Cement Road, large trees and houses on both sides of the road make the building appear much larger than it actually is, but then, once the road opens up, your perspective of the bay changes, and the building shrinks to its actual size. Others claim that the refraction of light from the bay’s shallow water also contributes to the optical illusion.

 

The visual effect of the Shrinking Mill illusion is so strong that it can be experienced on video. In fact, this is one of the main causes of its growing popularity as a local tourist attraction. The grain elevator has been there for more than 100 years, but people only started talking about the Shrinking Mill after clips of people driving by it started going viral on YouTube and Instagram.