High Knoll Fort stands 584 metres (1,916 ft) above sea level and is the largest, most prominent and most complete of the forts and military installations on the island. It is located to the south west of, and overlooking Jamestown. It is designated as a Grade I Listed building and is one of the 7 Wonders of St. Helena.
The current fort was built by the Royal Engineers in 1874, but this structure incorporated an earlier fort on the site built in around 1790 by Governor Brooke. This earlier fort comprised a high, square structure with two outer towers and stone ramparts. On Read’s 1817 map this fort was named “High Knoll Citadel”.
In 1816 Governor Lowe, as part of a general programme of improving the island’s fortifications, recommended High Knoll be made into a “Covering Fort” for Ladder Hill, providing a second line of defence if an enemy made a successful landing in James Bay and securing the high ground to the rear. Whether significant improvements were made is unknown. In Melliss’ “List of Guns” for 1825-36 High Knoll is listed as having two 14 pounder iron guns and eight 18 pounder carronades.In the 1860s and 1870s Britain went through a period often referred to as “fortification mania”. In this period it was decided that High Knoll should be substantially improved. The current structure is the result. The new fort had two purposes: It had many more guns trained on James Valley, to defend against an attack from that direction; and it was a redoubt fort, where the population of the island could shelter in case of an invasion (hence the size of the large central area).
Works began in 1874, as marked by the plaque over the gate, but were not completed until around 1894.
The fort has four water wells, each of approx. 60cm diameter, one within the tower area and the others in the main arena. The “Quarters” area is divided into rooms, many with small fireplaces. It is thought some were later used as stables.
Magnificent though the new fort clearly was, it never had the opportunity to fulfil its purpose. No enemies attempted a landing on St. Helena in its lifetime. It was briefly useful in the early 20th Century, to house some of the more difficult Boer Prisoners, but apart from this, and as the military presence on St. Helena gradually reduced, High Knoll Fort slowly became a disused monument; a place to visit to get a good view of the island.
The current iron gates are not original, and examination of the gate area shows the remains of a mechanism that would probably have operated a drawbridge.
In the 1970s the RAF had a satellite tracking station there. More recently it has been used to quarantine animals, and Sure South Atlantic have TV transmission equipment located there