The brick structure on what is known as Frog island is the remains of the railway bridge, built around 1870-71, which carried the Midland Railway Bedford line from the Engine Shed across the Nene and on into St John’s Station. Also visible is the remains of the embankment which ran along the western end of the park. The line then crossed Victoria Promenade on a viaduct and into the station, which is now occupied by the Universities St John’s Hall of residence and modern housing. The viaduct was in use until 1939, when the London Midland and Scottish Railway company chose to close St John’s Station and re-route its services to Northampton Castle Station. The line up to the viaduct was used as sidings until the late 1950’s until it was permanently put out of use. At this point the viaduct and the station were finally demolished.