Inside 'the worst building in the history of mankind'

North Korea hopes to complete within three years an ambitious but long-delayed hotel under construction in Pyongyang for 25 years, a travel firm said Friday after it was given rare access to the site.

The hotel has come in for much criticism over the years, with Esquire magazine once dubbing it "the worst building in the history of mankind".

Former North Korean leader Kim Jong-Il, who died last year, reportedly ordered construction of the 105-storey pyramid-shaped Ryugyong Hotel in 1987.

But the project has been repeatedly delayed and for many stands as a symbol of the persistent economic problems plaguing the country, a Stalinist state with a barely functioning economy that has suffered from famines in recent years.

As the North's economy took a deeper turn for the worse in the 1990s, the empty shell earned the nicknames "Hotel of Doom" and "Phantom Hotel."

Beijing-based company Koryo Tours, which organises trips to North Korea, was granted a rare glimpse of the hotel last week.

During the visit, manager Hannah Barraclough and a colleague were told that North Korean authorities "say it will be two or three more years before the building is complete".

Photos taken by Koryo Tours reveal a vast but still unfinished concrete interior.

"The atrium, when you walk into the hotel, is covered in glass and full of light," said Barraclough, adding that the glass cladding covering the hotel is nearly completed.

The hotel boasts a ninety-fifth floor viewing platform offering "an amazing panoramic view over Pyongyang" and it will house a massive banquet hall as well as offices and apartments, she said.

Barraclough added that the hotel is likely to remain closed to tourists until its interior is finished.

For a time, the North airbrushed images of the Ryugyong Hotel from photographs.

North Korea has one of the world's most rigidly-controlled economies and is desperately poor following decades of mismanagement and isolation, as well as the imposition of international sanctions over its nuclear programme.

Estimates published in South Korean have put the costs of completing the hotel and making it structurally sound at as much as US$2 billion (A$1.93 billion), more than 10 per cent of the North's yearly gross domestic product.

North Korea watchers and media reports in South Korea say Kim Jong-Un, who took over as leader after his father's death in December, has shown signs of promoting market reforms in a bid to stimulate the economy.