From about 1900, the colonial administrators of St. Kitts sought to arrest the deterioration of the once magnificent "Gibraltar of the West Indies" by allocating an annual sum for clearing brush. During the 1930s through 1940s a few committed individuals, outstanding among whom were George King and Malcolm Smith, worked tirelessly towards reclaiming some of the ruined structures from the bush and bringing to the attention of others the wonderful treasure lying almost unnoticed at Brimstone Hill.

Then in April 1965, the Brimstone Hill Restoration Society was founded at the instigation of the then Administrator, Lt. Colonel. H. A. C. Howard supported by the then Premier, Robert L. Bradshaw. Other founding members included Sir Geoffrey P. Boon, Frederick Kelsick and D. L Matheson. Matheson it was who took on the mantle of leadership in 1967, and for two decades, with the aid of a few stalwarts and the support of the Public Works Department, the British Development Division and a few benefactors, took on the formidable tasks of stabilisation of ruins, and the promotion of public awareness of the heritage value of the Brimstone Hill Fortress.

In recognising the historical and cultural value of the Brimstone Hill Fortress and in the work of the Society in its preservation and promotion, the Government in 1987 enacted legislation which designated Brimstone Hill Fortress a National Park, and empowered the Society to administer it.

The Brimstone Hill Fortress is considered by many experts to be an outstanding international architectural monument. The Citadel, for example, is one of the earliest and best preserved examples anywhere of a type of fort construction known as polygonal fortification. The system of water catchment and storage, as well as the adaptation of barracks, bastions and other structures to the steep-sided Hill, are marvels of engineering.

Designed by military engineers, this immense fortress was built largely by African slaves, many of whom possessed certain skills including stonemasonry. English military artificers (soldiers skilled in various trades ) were also involved. However, because of the prevailing 17th century notion that Europeans could not long survive exposure to the strong tropical sun, the work of maintenance and other essential services were provided by slaves