Secret headquarters of world's most sophisticated spy services revealed

A nondescript red brick building tucked away beside a pub near a park in central London was revealed on Friday to have been the base of one of the world's most sophisticated spy services - Britain's GCHQ eavesdropping agency.

Tucked away between a Starbucks cafe and a pub that specializes in fish and chips, an unassuming office building in downtown London has been the secret headquarters to one of the most powerful intelligence agencies in the United Kingdom.

Since 1953 the Government Communications Headquarters (GCHQ) has worked to protect the UK's national security by intercepting communications, employing expert codebreakers and more recently combating cybercrime and terrorism from its now-defunct building on a narrow street near St Jame's Park.

The GCHQ and the experts that walked through the secret doors of its Palmer Street site played a key role during World War II and the Cold War.

The secret history of this red brick and stone building with old factory-style windows was only revealed by the GCHQ once the eavesdropping agency had abandoned the building for another venue.

The only thing that could have given away the building's true mission was several discreet security cameras on its facade.

The GCHQ has, in recent years, been the source of some controversy after Edward Snowden revealed the so-called Tempora operation: a government-sponsored worldwide mass surveillance exercise that collected data from the Internet of public and private citizens.

Snowden's investigation revealed that the GCHQ intercepted fibre-optic cables for Internet communications that connected throughout the UK and beyond to the European Union and the United States. 

The ambitious project, which was capable of collecting 10 gigabits of data per second, was made up of two key projects with grandiose names: "Mastering the Internet" and "Global Telecoms Exploitation," according to Snowden. 

Ever since the scandal broke, the intelligence agency - which works alongside the MI5 (the UK's domestic security agency) and MI6 (the foreign intelligence agency) - the GCHQ has launched a campaign to present itself as a more transparent institution. 

This year will mark the organization's centenary and there has been a big drive to share the GCHQ's history with the British public.

A highlight the spymasters have been keen to celebrate was the end of World War II (1945) which came about after GCHQ codebreakers were able to decipher the coded messages of the German Nazis using the "Enigma" machine.
 

The GCHQ has sold the building to a private company and has not yet revealed what its future will hold.

The intelligence organization has also confirmed that its main headquarters will continue to be in the capital but has not revealed where this might be.

Even though the GCHQ still keeps many things under wraps, the drive for transparency meant it became the first spying agency in the UK to launch a Twitter account in 2016.