He had scaled the wall several times before, but this time it was more than just a worker evading the authorities. It was the first giant leap towards freedom for the countries in Central and Eastern Europe.
It was the morning of August 14, 1980, and Lech Walesa had just joined his fellow strikers at the Lenin shipyard in Gdansk.
They had seized control over their workplace to protest against a recent rise of food prices, among other things.
Seventeen days later, Walesa appeared before them triumphantly and told them that they would be able to have "an independent, self-governing trade union" and had won "the right to strike."
Their stocky and mustachioed leader had cajoled Poland's communist government into granting workers the right to organize freely and to strike -- a move not yet witnessed in any other Warsaw Pact country.
He had also chaperoned the creation of the first independent trade union, Solidarnosc (Solidarity), in the Soviet bloc. Within months it had 10 million members, more than one-quarter of the country's population.
It was an electrician -- with no higher education -- who had triggered what came to be seen as one of the key events leading to the downfall of communist regimes in Central and Eastern Europe.
Hailed in the West as a champion of rights and liberty, Walesa remains, however, a more controversial figure at home in Poland, where he has faced criticisms of his management style and fought off allegations that he collaborated with the former communist authorities.
Walesa was born 70 years ago on September 29, 1943, in the small village of Popowo between Warsaw and Gdansk.
He started at the Gdansk shipyard in 1967 and by the following year he was already encouraging colleagues to boycott official rallies that condemned the ongoing student strikes.
In 1970, he was one of the co-organizers of an illegal strike at the shipyard. It ended in failure and 30 dead workers but it also galvanized Walesa.
Throughout the 1970s he was involved in underground unions, strikes, and campaigns. The secret police had him under constant surveillance and in 1976 he lost his job at the shipyard.
After the historic moment of Solidarity's founding in 1980, events took a turn for the worse. Martial law was declared in December 1981 and Walesa was imprisoned for 11 months near the Soviet border as Solidarity was outlawed.
It was time for underground activities again, but this time he had both history and powerful backers, such as several Western governments and the Catholic Church, led by his compatriot, Pope John Paul II, on his side.
Walesa received "Man of the Year" honors from "Time" magazine and others, in a surge of world renown that was crowned with his acceptance of the Nobel Peace Prize in 1983.
His second moment in the international limelight cam in 1989 -- and once again he outfoxed the ruling Communist Party.
During political talks known as the Round Table Negotiations, he was invited to represent Solidarity amid growing social unrest. The seasoned striker not only managed to secure the legalization of independent trade unions, he also signed a 400-page agreement on sweeping political and economic reforms.
In the elections later that year, the entire upper house of a newly created bicameral legislature could be contested freely, as well as 35 percent of the seats in the lower chamber. With Walesa as its poster-boy, Solidarity made a clean sweep.
He didn't run for parliament, but soon became disillusioned with his representatives' apparent willingness to govern alongside the communists.
He therefore decided to run for the newly reestablished office of president in 1990, using the slogan, "I don't want to, but I've got no choice" ("Nie chce, ale musze."). He won easily.
In August, 2010, Walesa reflected on these changes at an event in Gdansk marking the 30th anniversary of the Solidarity movement.
"If anyone had told me then that I would live to see a time when there would be no communism and no Soviets in Poland, that Poland would be sovereign and independent, I would not have believed that we could achieve that," he said.
The Polish people's love affair with Walesa began to fade not long after his election.
During his five years in power he discovered that organizing strikes and negotiating deals with a fumbling regime was not the same as heading a country beset with economic and social problems.
He managed to negotiate the withdrawal of Soviet troops from Polish soil, won a substantial reduction in Poland's foreign debts, and started the first arduous steps towards Poland's integration into the European Union and NATO.
A Nastier Side
But Walesa revealed a nastier side, too -- that of a president constantly at war with former Solidarity allies, leading to never-ending governmental changes. Charges that he was authoritarian, rude, and too undignified to lead the country became common.
Suddenly, a poorly educated and highly devout peasant with eight children was seen as not fit to guide Poland toward the West. That he was perceived to be arrogant and handled media poorly only compounded the situation.
Walesa ran for reelection in 1995 but lost. He tried again in 2000, but got an embarrassing 1 percent of the vote.
With his role in politics marginalized, he turned to lecturing at various universities and organizations, mainly abroad, where his reputation as a freedom fighter was still solidly intact.
Accusations that he had been an informer for the communist secret police in the 1970s dogged him on and off over the years.
Walesa has always denied the charge, but in 2011 he acknowledged to "The Guardian"
newspaper that he had spoken to the secret police, though he added, "Not for a moment was I on the other side."
One enduring legacy of the Solidarity leader was by then already secured by the tourists flocking to his adopted home city of Gdansk, many through its Lech Walesa International Airport, to see those shipyards.
His workshop and the wall were still there, but they would now overlook the ever-growing number of new office buildings, shops, and apartments slowly edging out those old echoes of humming cranes and protesting workers.