The King's Lines are a walled rock-cut trench on the lower slopes of the north-west face of the Rock of Gibraltar. Forming part of the Northern Defences of the fortifications of Gibraltar, they were originally created some time during the periods when Gibraltar was under the control of the Moors or Spanish. They are depicted in a 1627 map by Don Luis Bravo de Acuña, which shows their parapet following a tenaille trace. The lines seem to have been altered subsequently, as maps from the start of the 18th century show a more erratic course leading from the Landport, Gibraltar's main land entrance, to the Round Tower, a fortification at their western end. A 1704 map by Johannes Kip calls the Lines the Communication Line of the Round Tower.