On a leafy boulevard in downtown Havana, a man is beating himself with a sledgehammer, on his wrists, elbows and forearms, drawing a crowd of passers-by who gather to film the spectacle with their phones.
What shocks the crowd is not the apparent self-mutilation, but rather the fact that he appears to come away unscathed.
Cuban "Ironman" Lino Tomasen said he once aspired to be the next Mike Tyson.
Tomasen trained to become a professional boxer by subjecting himself to millions of blows with the hammer, and eventually moving from the Caribbean island to fight in Mexico City.
"I had 27 matches won by knockout, but I retired because in the last of them I fractured the skull [of my opponent] and he died instantly," he said in Havana.
"I gave away all the money I made in my fights to his family. I vowed never to fight again."
Tomasen, 32, estimated that he gave the family more than $100,000, a huge amount of money for most Cubans.
He has since written off fame and fortune, and makes a far more modest living on the streets of Havana and nearby beach communities, collecting tips from impromptu shows.
On a recent sultry summer morning, Tomasen chewed on a half-smoked cigar and amazed a crowd by doing push-ups on his bent wrists with a full-grown man on his back.
Then he returned to beating himself with his hammer, pounding every joint in his arm to the winces of onlookers.
"It's all real, nothing fabricated," said Edward Carbonell, who watched Tomasen in awe. "He did some push-ups with me on his back."
Tomasen said he was content now to serve as an inspiration for those who strive to break barriers and had no regrets in leaving behind a career in boxing.
"They have offered me thousands, millions of dollars to get back into it, because they know my potential that I have, and I have always said no," he said.
"I want to be remembered as someone who pushed the limits of what was possible."
