Scientists say it's a mirage, but others swear that when the weather is right, Clevelanders can see across Lake Erie and spot Canadian trees and buildings 50 miles away.
Eyewitness accounts have long been part of the city's history.
"The whole sweep of the Canadian shore stood out as if less than three miles away," a story in The Plain Dealer proclaimed in 1906. "The distant points across the lake stood out for nearly an hour and then faded away."
"I can see how this could be possible," said Lawrence Krauss, chairman of the physics department at Case Western Reserve University.
Krauss and Joe Prahl, chairman of the mechanical and aerospace engineering department at Case, said mirages can occur during an atmospheric inversion, in which a layer of cold air blankets the lake, topped by layers of increasingly warm air.
When this happens, it can cause the light that filters through these layers from across the lake to bend, forming a lens that can create the illusion of distant objects.
The scientists said the air has to be extremely calm for the mirage to appear. If the wind blows, it distorts or dissolves the image.
Prahl and Krauss said such a mirage is rare. But Tom Schmidlin, a meteorologist in the geography department at Kent State University, said it's hardly unheard-of.
"It's not terribly unusual. Sailors are always exposed to this kind of thing," he said.
Prahl, who regularly sails his 30-foot sloop Seabird from Cleveland to Canada, has never seen it.
But Bob Boughner, a reporter for the Chatham Daily News in Ontario, said he's seen Cleveland from across Lake Erie twice, the first time four summers ago while driving along a road near the lake. He saw it again two summer ago while driving along the same road.
All of a sudden, there was Cleveland, just off the Canadian shore, as if it were just across a river, he said.
"I happened to look across the lake and, geez, I couldn't believe the sight," he said. "I could see the cars and the stoplights. I could even make out the different colors of the vehicles. It lasted a good two or three minutes."
Boughner said he remembers his aunt Melba Bates, who lived all her life on Lake Erie and recently died in her late 90s, talking about being able to see Cleveland, but he didn't believe her.
"I thought she was making up stories," he said. "But sure enough, I could see the same damned thing. When it shows up, it looks like you can touch it."