This initially controversial cut and cover tram tunnel was conceived in 1898, when the area at the time was a slum. London County Council wanted to clear the slum to open up new streets, and the area was subsequently cleared. Parliamentary permission was granted in 1902, and the tunnel was opened to  the public in February 1906, with a route from Angel to Aldwych using single deck trams. The increased use of double deck trams in the late 20s, meant the tunnel height was increased and the tunnel lowered in 1930. It re-opened in 1931, but only 2 years later, the newly formed passenger transport board took over London transport, and decided to replace trams with more modern buses. However diesel buses couldn't operate in the tunnel without increased ventilation issues. The tunnel was closed for good for public transport in 1952, when all tram usage in London stopped.

In 1964, the southern end of the tunnel was re-used for general traffic, with an underpass to the strand and Waterloo bridge. The last exit/entrance to the tunnel was underneath Waterloo bridge and it was sealed off until 2007, when the Buddha Bar was opened on this spot. More info and old photos of the tunnel in use can be found on subbrit's site.
The posting of pics by another explorer alerted us to the fact it was still 'do-able', however unlike Ds, our shoes remained in tact. I teamed up with Gringz, and we wandered amongst those looking for inebriation. Access wasn't easy, as the gates are rather formidable, and a crime camera watching from the other side of the street provides the need for quick decisive action. The tram inbound and outbound tram tracks are still visible leading down from the now, only access to the tunnel.

Looking down the access ramp into the tunnel. A subsequent trip in the early days of 2011 with Urbanity, saw that this area is now heavily flooded, and impassable for vehicles.

The split, where the trams take different sides to pass the tram stop that sits in the tunnel.

Approaching the tram stop

Looking back towards the access point, note the small pool of water, which has now flooded.

The tunnel is now used for storage by Camden borough council, including an array of street signs.

Huge amounts of stone and small rocks were stored here as well.

Old christmas street decorations are also stored down here.

Old gas lamps have also been laid to rest here.

A prop from the 2008 film The Escapist. The stop was never called Union Street, it was Holborn Station.

The original exit to the street, a similar one sits at the other end of the stop behind the camera

A map created for the film The Escapist.

Sitting on old gas lamps on was once the tram station.

The station as it is now, from the approach.

A photo from The Daily Mirror of how it once looked

The right wall follows the original exit route onto the Strand, the left wall was built for the traffic underpass to Waterloo bridge.

Supports for the traffic underpass and utility cables.

Some sort of utility rooms, built underneath the slope into the traffic underpass at the southern end of the tunnel.

And with that, Kev and I returned to the night air and wobbly drunks not caring what we were up to.