A team of urban explorers have accessed all the tunnels and culverted rivers that run under Bristol city centre, and for the first time mapped them out in one entire video.
The team, led by veteran urban explorer Matthew Williams, travelled into the maze of underground rivers and tunnels by boat from the Floating Harbour close to Castle Park View.
The video, which has now been published on the 'Secret Vault' YouTube channel, is more than an hour long, and consists of ethe explorers traversing along the tunnels either on board a boat or, when water levels are too shallow, by wading through the water, with the route of each section of each tunnel explained using a satellite image showing the route from above ground.
The group first travelled by boat along the course of the old medieval moat that formed an artifical protection for the city and effectively turned the old city inside the walls into an island, by connecting up the River Avon and the River Frome.
That medieval moat still exists, in the form of a culverted channel that helps regulate water levels in the Frome and in the Floating Harbour.
The main junction, which can be accessed directly from above ground through a door in the wall of Castle Park close to the Eclipse tower, is the spot where that moat meets the River Frome underground, and nearby where a fourth tunnel diverts across to the Floating Harbour as an overflow. It acted as 'base camp' for the explorers during their epic expedition.
The team walked underground to the mouth of the River Frome, under The Galleries shopping centre, and following the curve of the River Frome, which once flowed out in the open air through the centre of Bristol. At various points, the team pause and look up to see manhole covers in the roof of the tunnel, where they can hear vehicles and people on the streets above.
The course of the Frome largely follows the course of the A38 Rupert Street, as it curves southwards into The Centre, underneath the Cenotaph and along St Augustine's Parade, before emerging into the Floating Harbour next to the Cascade Steps by the Watershed.
The team turn back just before they reach that point, but the rest of the video sees them investigate other tunnels that criss-cross the underground under the city centre. The epic video ends with a long walk upstream in the Frome, all the way under Cabot Circus and Temple Way, to emerge - at night time by this point - at the spot in St Jude's where the Frome flows from the open air into the tunnel system.
Mr Williams turns back and spots a warning sign not to enter the tunnel - a reminder that exploring the tunnels under Bristol is not recommended.
Its obviously not the first time the river and flood management tunnels under Bristol city centre have been explored - indeed, one tour guide in Bristol before the pandemic even floated the idea of taking tours on a boat along the course of the underground castle moat, and many others have ventured down the River Frome to emerge at Cascade Steps before.
But it is the first time an exploration of all of the tunnels has been undertaken and compiled into one video, with an above-ground comparitive explanation of the routes taken below.
Mr Williams is a veteran urban explorer, and in 2020 led a team into the two empty landmark buildings opposite Temple Meads station - including the discovery that the basement bar under the Grosvenor Hotel was still largely intact.
Later in 2020, Mr Williams led a team to become among the first people to explore the 650-year-old tunnel system that once ran underground from Totterdown to the city centre, and was dug by monks to provide fresh water for the city.
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