Running for 2.5 miles (3.6km) beneath Newcastle, the Victoria Tunnel is one of the city's "hidden relics". Opened in April 1842, it was used to transport coal from Leazes Main Colliery near the Town Moor down to the River Tyne.
The waggon way was an important part of the industrial age in the country, shipping coal from the North East down to London and the South East. The colliery closed in 1860.
Part of the tunnel was filled in where the colliery had been and it was split into three sections. Engineers regularly inspect the tunnel to ensure its safety. Most of its seven entrances have now been sealed off at the surface and only 700m (2,300 ft) of the tunnel is accessible.
It is believed that in 1928 a section of the tunnel towards the river was used to grow and sell farm mushrooms during the recession.
The tunnel was largely forgotten about until 1939, when it was converted into an air-raid shelter during World War II. More than 9,000 people spent hours in the tunnel in "smelly, damp and cold" conditions. The impressions of the wooden benches and bunk beds can still be seen on the floor of the tunnel.
One of the mysteries on part of the 19th century tunnel wall is underneath Blackfriars Hall. Made from concrete, it is a cross with Jesus and a plaque reading 'roll of honour'. The trust believe it could be from World War II but little is known about who put it there and why.
In 2010 the Ouseburn Trust took over the running of the tunnel and opened up part of it to the public for guided tours. "People are fascinated by the fact you are 60 to 70ft underneath people walking along the pavement and they are totally oblivious about it," said tour guide Mel Deighton.
Mr Deighton said: "It is part of Newcastle's history and it is important people in the North East can see these precious relics from World War II which affected ordinary people's lives."
Now, more than 170 years since it first opened, the Victoria Tunnel is hosting its very first art exhibition Into The Dark. The 12-hour underground show on 12 June will feature work from 12 street artists from around the world.
