The bastions (north and south) are located along the Line Wall Curtain on the West Side of Gibraltar. They take their name from a Captain William Jumper who was one of the first officers to land ashore and capture the existing Spanish bastion on this site during the Capture of Gibraltar in August 1704. According to George Hills, the first two captains to come ashore were called Juniper (sic) and Hicks. They were sent by Captain Edward Whitaker when he saw that the Spanish guns covering the New Mole had been put out of action.