One of the things you can do with disused railway tracks is turn them into bike trails or hiking routes. There's a few that have been so converted in Mayenne; the one we tested runs from an unremarkable and un-named place north-east of Laval, North towards the town of Mayenne.
The start point is quite literally a point where an old railway bridge crosses a road, and there is a slip-lane you can take that leads up to the track. There is no parking there, so we drove along a couple of Km to where there is a proper car park.
As with the towpath along the Mayenne river that we tested the other day, the railway line was very close to level, but unlike the towpath it was straight. This made for a rather boring ride.
There were occasional points of interest as the track passed old station buildings, or went over or under bridges, but the interest to be had was in spotting landscape features through the trees. The track had been well signposted, with adequate warnings for what used to be level crossings, with notices showing how grinning cars will joyously crash your bike if you're not careful.
We had a pleasant pic-nic when we got to Commer (About 10km from our car park) and then set off back. The weather was fine, the route calm and quiet, and the general atmosphere peaceful. We will doubtless test other sections of the track, but the winner so far in terms of interest en route, is the Mayenne towpath.