Few souls have been able to venture down the historic Broomieknowe Tunnel near Edinburgh in recent years.
That's because for the past six decades, the abandoned railway tunnel, which runs for 393 metres beneath Broomieknowe between Bonnyrigg and Lasswade, has been sealed off from the outside world.
Built back in 1867 by Sir Thomas Bouch, the esteemed railway engineer and designer of the ill-fated Tay Bridge, the subterranean link was a part of the Esk Valley Railway and integral to the success of the local paper mills to the south of Edinburgh.
