Originally called Muralla de San Benito (English: St. Benedict's Wall), it was built in 1540 and strengthened in 1552 by Holy Roman Emperor Charles V. The wall remains largely intact and extends from South Bastion, which was once at the water's edge in the harbour, to the top ridge of the Rock of Gibraltar.

The lower section of the wall runs up from the South Bastion which was once at the water's edge in the harbour, to Prince Edward's Gate at the base of a steep cliff.

[2] Calvi designed a wall that ran west–east in a straight line from the coast for about 280 metres (920 ft) until it reached a precipice.

[8] Philip II succeeded Charles V in 1558, and commissioned the Genovese engineer Giovan Giacomo Paleari Fratino to continue the improvements.

[4] In 1627 the Spaniard Luis Bravo de Acuña wrote a treatise on the fortifications of Gibraltar for King Philip IV of Spain.

[10] In July 1704 combined forces from the United Kingdom and the Dutch Republic led by Sir George Rooke, captured Gibraltar during the War of the Spanish Succession.

A force of five hundred volunteers led by Spanish Gibraltar-born goatherd Simón Susarte managed to scale Charles V's Wall, and massacred the guard at Middle Hill, but were attacked by a party of grenadiers and were all either killed or captured.

[15] Inglis Way, one of the walks within the reserve begins at Queen's Gate near the foot of the upper section of the wall at Prince Ferdinand's Battery.