Darenth Country Park
This country park in Dartford has some nice cycling and walking trails to try. The park has a decent sized car park just off Gore Road, near Darent Valley Hospital. From here you can pick up the 1 mile circuit around the park. The park has nice wide lawns, picnic areas, meadows and pockets of woodland. The area is popular with dog walkers and joggers.
You can extend your walk by heading east and exploring Darenth Wood. Eventually you will come to Bean and the pretty Beacon Wood Country Park. There's more nice woodland trails here.
About 1 mile to the west of the park you can pick up the Darent Valley Path. This splendid long distance trail will take you along the River Darent to Farningham where you will find the pretty Farningham Woods Nature Reserve.