Old Warden Tunnel - Nature Reserve

Old Warden Tunnel Nature Reserve

This nature reserve, once part of the railway line between Bedford and Hitchen, is a haven for a wide variety of vegetation and animal life. The scrub and trees provide shelter and food for a number of different species of birds and management is helping to encourage flowers such as the pyramidal orchids and cowslips.

How To Get There By Passenger Transport

Bus: Bedfordshire Bus Info line: 01234 228337, Mon - Fri 8.30am - 5pm
Travel Line: 0870 6082608, 7 days a week, 7am -10pm
Train: National Rail Enquiries: 08457 484950 24 hour service
Click here for the National Rail Enquiries website

How To Get There By Car

The Old Warden Tunnel reserve lies between Cardington and Old Warden. Turn left from the A1 at the roundabout to the north of Biggleswade and follow the signs to Old Warden. From Old Warden follow the signs to Cardington.
Access to the reserve is via the Greensand Ridge path. You may park with care at the roadside near the path.

Start/Finish Point

The reserve is accessed 200m along the Greensand Ridge walk that leaves Bedford Road between Old Warden and Cardington.

Access and General Information

Surface Types: You will walk across surface types of grass or uncultivated earth paths with and without ruts and mud.
Linear Gradient: The steepest linear gradient is steeper than 1:6 at the north-western entry to the reserve.
Cross Falls: The steepest are 1:9 or steeper at the top of the tunnel.
Width Restriction: There is a width restriction of 790mm on the sleeper bridge.
Steps:There are 153 steps down to the tunnel entrance – these have a maximum step height of 230mm.
Barriers: There is one kissing gate with a restriction of less than 1000mm (at the Greensand Ridge entry point) and two 2-step stiles.
Refreshments: None recorded.
Public Toilets: None recorded.
Picnic Tables: None recorded.
Seats: There are one seat overlooking the railway cutting.

Points of Interest

Old Warden Tunnel Nature Reserve contains 2ha/4,95acres of calcareous and neutral grassland, scrub and woodland on a cutting and tunnel constructed to take the London, Midland & Southern Railway’s main line from Bedford to Hitchin. Opened in 1857, the line closed in 1963, but before the rails and sleepers were removed it had a brief moment of fame when part of ‘Those Magnificent Men in their Flying Machines’ was filmed here in 1964. The Wildlife Trust has leased the reserve since about 1973. The Old Warden Tunnel reserve conserves the slopes of the cutting, covered with species-rich calcareous grassland and some scrub, and the north tunnel baulk, created when soil excavated from the tunnel was piled above it The tunnel itself is not part of the reserve and is blocked to permit access only for the bats that roost there.


Scrub and trees provide food and shelter for birds, but would soon expand over the grassland if the site was not managed. Regular mowing or scything prevents scrub invasion; the grass cuttings are removed to reduce the levels of nutrients that would favour fast-growing grasses rather than wild flowers.

Rabbits were introduced to Britain from the Mediterranean by the Normans about 1000 years ago. Originally so tender that burrows had to be excavated for them, rabbits are now so common they may do serious damage to woodland and grassland.

Below are some of the plants that indicate calcareous or neutral soils at Old Warden Tunnel.



The Wildlife Trusts, supported by Bedfordshire Growers Ltd. Illustrations by Sarah Wroot.

You can help to protect this and other important sites by joining the Wildlife Trust. If you would like more information about this Nature Reserve or other reserves in Bedfordshire, please contact the Reserves Manager, The Wildlife Trust, Priory Country Park, Barker's Lane, Bedford MK41 9SH or email