Brimstone Hill Fortress National Park is a UNESCO World Heritage Site of historical, cultural and architectural significance. Over the course of 100 years, it became an almost natural outgrowth of the 800-foot hill from which it emerged; a monument to the ingenuity of the British military engineers who designed it and to the skill, strength and endurance of the African slaves who built and maintained it. The steep slopes of Brimstone Hill had to be tamed by the disciplines of engineering and architecture, and at the risk and probable loss of human lives. The walls of the structures are predominantly of stone, laboriously and skillfully fashioned from the hard volcanic rock of which the hill is composed. The mortar to cement the stones was produced on site from the limestone that covers much of the middle and lower slopes. Begun in the 1690s, the Fortress finally took shape as a complete military community in the 1790s, and as such is it is a veritable time capsule of international significance. What's more, the prominent Citadel is one of the earliest and finest surviving examples of a new style of fortification known as the polygonal system. The physical location of the Fortress presents attractive panoramic vistas of forested mountains, cultivated fields, the historical township of Sandy Point, and neighbouring Dutch, English and French islands across the Caribbean Sea.