Combe Down tunnel has light and sound display installed
An interactive light and sound display is being installed along the length of a disused railway tunnel in Bath.
The mile-long (1.6km) Combe Down railway tunnel is being converted for cyclists and pedestrians by a cycling charity called Sustrans.
The tunnel will be part of a longer route which cuts through the south of Bath avoiding the hilly parts of the city for cyclists and walkers.
Once it opens next April it will be the longest cycling tunnel in Europe.
The tunnel will also create a 13-mile (21km) loop between Bath and Midford via the canal towpath in the city.
Combe Down tunnel is part of a project called the Two Tunnels Greenway.
Devonshire railway tunnel at Bloomfield will also form part of the new Two Tunnels Greenway route, which runs through Linear Park and over the Tucking Mill Viaduct.
The Two Tunnels project aims to create a bigger cycle network in Bath and will enable cyclists to access other cycle routes in Bristol and the southwest.
Sustrans has estimated more than one million journeys are expected to be taken on the tunnels route every year by both local people and visitors to Bath.
Frank Tompson, chairman of the community-based Two Tunnels Group, said: "It's been a long journey since some of us stood between the bricked-up Devonshire and Combe Down tunnels and said, 'wouldn't it be a good idea if...?
"Six years on and the end is in sight."
The route is part of a national project from Sustrans and has received backing from the Big Lottery Fund.