The British started fortifying the double peaked Brimstone Hill in 1690. Sitting at around 800ft it offers commanding views of the coastline and neighbouring islands and with such a steep approach was considered impregnable, the Gibraltar of the Caribbean. Hyperbolic perhaps but it did see some action against the French over the years before being abandoned in 1853. It has since been partially restored and is a pleasant though not outstanding visit if one is in St. Kitts. 

Our visit was in Feb 2024. We were on a cruise with a full day stop in St. Kitts. There is no public transport to the fort and rather than take a tour we found a van taxi to take us to the fort and back with about 1 hour of waiting time for $100US. Entry is a pricey $15US now. It is a steep road uphill from the coast and would be a hot and unpleasant walk so we were grateful for the ride. There are various levels of fortifications as you ascend and then a final short hike up one of the peaks to the restored citadel on top. An hour is enough time for a quick look around the citadel and it's few displays, admire the views and then walk over to the barracks and ruined officer's quarters at the base of the other peak. With more time I would have wanted to pack a lunch and just have a picnic more than anything else. Surprisingly for a major attraction in this small country, even with a large cruise ship in port it was still not crowded and maintains an air of respectable authenticity.