Nigel writes: This evening's ride to Barton attracted four riders: Rob, Steve, John E and me. Perhaps the others thought the dark sky at 6pm heralded rain. if they did they were mistaken: the clouds soon disappeared and we enjoyed a warm, and sunny, if breezy, evening.
We set off south out of Cambridge along the busway cycleway and DNA path to Great Shelford. From here we continued south through Stapleford to Sawston, where we turned west onto the new cycleway to Whittlesford.
At Whittlesford we turned north-west to Newston and Harston. Part-way along this road we stopped and turned into a field. Steve led us to a small concrete structure with a metal hatch on top.
Steve lifted up the hatch - to my surprise it wasn't locked - and we peered in: a metal ladder led down to an underground chamber below.
Apparently this is a Royal Observer Corps Monitoring Post from the Cold War. It would have been easy to climb down, but cycling in the sunshine was a more attractive prospect and we were soon back on our way.
We continued north-west through Haslingfield, Harlton and the Eversdens to Kingston where we turned back east for the final few miles to Barton where we stopped at the White Horse. It now 8.20pm and still light, though the sun was just about to set. We sat outside in the gathering gloom consuming beer and chips before returning back in the dark to Cambridge. I arrived home at 9.30pm, having cycled 30 miles.
View this GPS track on a larger map