Polish TV presenter Robert Bernatowicz used to hate Warsaw's colossal Palace of Culture, an unwanted gift from Soviet dictator Joseph Stalin that opened 60 years ago this week. But that was before he broke into the building.

"I heard there was a tunnel where a fancy secret train ran between the Communist Party's headquarters and the palace. And I had this vision I'd find it," he told AFP.

The caper -- which involved shovels and repairmen outfits to fool the scary, baton-wielding police -- was ultimately a flop but left Bernatowicz with a soft spot for the palace.

"I forgave it all its years of communism and even recognised in it a kind of charm," said the 47-year-old, who went on to organise a bike ride along the facade that made it into the Guinness Book of World Records.

The tallest building in Poland -- often seen as a communist rip-off of the Empire State Building -- has been variously described as a rocket, a UFO or a drunken confectioner's crazed dream.

Long a reminder of Soviet oppression, the building inspired by Stalin's jealousy of Manhattan's skyscrapers was once so disliked by Poles that they joked the best view of the city was from the palace because it was the only place you could not see the building.

Subtle it was not. The monumental 237-metre (776-foot) edifice towers over the biggest square in Europe.

But with the passage of time, "attitudes have changed and I think the vast majority of Poles like the palace," said Michal Murawski, a 31-year-old cultural anthropologist who wrote his PhD about the building and can regale you for hours with fun facts about it.

"There is a real explosion of interest in the palace... There's more going on there than there has been for years," he said.

"And that's what makes Warsaw unique: that it's a big city centred around this one absolutely crazy, extraordinary but very subversive building."

- Twilight zone -

Unveiled in July 1955, the 42-storey structure was built as an expression of fraternal socialist brotherhood on the rubble of a city centre almost entirely flattened by Poland's Nazi German occupiers in the final months of World War II.

Stalin cynically halted the Red Army's advance on the edge of the city to allow the Germans to crush Polish resistence, many historians believe.

The palace entered a kind of twilight zone when Poland threw off communism in the 1990s. Critics called for the symbol of the old regime to be pulled down, while others proposed wild plans like turning it into a botanical garden with palm trees and exotic animals.

"This Polish Virginian businessman called John Kowalczyk wanted to buy the palace and turn it into an international business centre, and redesign it in a terrible way," Murawski said.

Negotiations continued until Kowalczyk was shot dead in a parking lot in 1993, purportedly by his former father-in-law over extramarital affairs, a dramatic episode that "put an end to the idea of privatising the palace".

Though campaigners still call for its demolition -- a new letter was sent to the city this week -- the palace has been able to rest easy since it was listed as a historic monument in 2007.

- Jagger ate flowers -

There is little, if anything, the palace has not seen over the years: from a Rolling Stones concert where Mick Jagger ate carnations given to him as a welcoming gift by authorities, to Poland's first striptease show, to a book fair during communist times where vendors turned a blind eye to Poles pocketing banned Western literature.

It even saw a gathering of adherents of the UFO religion Raelism.

"My favourite story," said Magdalena Budzinska, who has compiled an anthology of six decades of journalism about the palace, is the one about the resident "crocodile brought over from Berlin" who would snap his jaws when you called his name.

Today the palace is home to around a dozen cats for rodent control, falcons in the tower that have a webcam recording their every move and, according to some, the ghosts of the many suicide jumpers and Soviet builders killed on the job.

Events organised in honour of the July 22 anniversary include a race up the 30 floors to the observation deck -- the stairs have 790 steps -- tours of the secret passages, a Tetris videogame contest projected onto the facade, and a birthday party with a cake.

Special guest Michal Ogorek, a Polish satirist, feels a particular kinship with the palace -- he was born the day it was unveiled.

"At 60, I think I'm probably the one holding up better, because no part of me has fallen off yet," he joked.

"That said, the palace is of an unbelievably robust design. They've knocked it down so many times in films, and yet it's still standing. (In one, the building is demolished with the pull of a toilet flush.)

"The palace is like a beast," he joked. "It will outlive us all."