Walk westwards and after about a mile is Sandsfoot or Weymouth Castle and gardens. This was completed on the orders of Henry V111 in about 1539 to support Portland Castle in the protection of Portland Harbour. It has 2 storeys, dungeons, cannons and quarters for 50 men. The castle was in bad repair by 1584 due to damage by the sea and remedial work had to be done. It was held for the king in the Civil War and was then used as a mint. It then became a storehouse and never saw serious military action.
Portland Harbour was built in Victorian times and was an important naval base during the times of the Spanish Armada. It was closed (under the then name of HMS Osprey) in 1999 and the work transferred to Somerset. The cycle track along this stretch is part of The Rodwell Trail and follows part of the old Weymouth to Portland railway line which was closed in 1965. Look out for the platform and a sign of one of the old stations.
Look out for the grim facades of the Young Offenders Institution and prison at Grove with the barbed wire and cameras. Near the end of the walk, on a hill near Fortuneswell, is an impressive sculpture of a quarryman. Descend into Fortunewell where there are buses back to Weymouth if needed.