Old Warden Tunnel nature reserve is a 3.8-hectare (9.4-acre) nature reserve near Old Warden in Bedfordshire. It is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire. The site is on top of a disused railway tunnel, Old Warden Tunnel.[1]
The site has oak and ash woodland with mature blackthorn and hawthorn bushes, and a steep cutting with grassland and scrub. Flowers include dwarf thistle and pyramidal orchid, and the scrub provides nesting sites for birds.[1]
There is access by a track from Southill Road.[1]
https://link.medium.com/lA6o8F7o4ab
52°05′20″N 0°22′34″W / 52.0889°N 0.3762°W / 52.0889; -0.3762