You might have noticed the exclusion zone covering the southern half of the island and how Plymouth is labeled as abandoned. Plymouth was the former capital of the territory and is still the de jure capital. However, on the 18th of July, 1995, the previously dormant Soufrière Hills volcano became active and started erupting. The eruptions destroyed the city and forced two-thirds of the islands population to flee, mostly to the United Kingdom. Since then, the largest city on the northern half of the island, Brades, has acted as the de facto capital, though a new capital, Little Bay, is under construction.
Even to this day, the volcanic activity from Soufrière Hills continues, mostly affecting the vicinity of Plymouth, including its docking facilities, and the eastern side of the island around the former W. H. Bramble Airport, which was buried by flows from the volcano on February 11th, 2010. Montserrat has been called a "Modern-Day Pompeii" in the Caribbean because of all this volcanic activity and destruction. The exclusion zone that extends from the south coast of the island north to parts of the Belham Valley was set up because of the size of the existing volcanic dome and the resulting potential for pyroclastic activity, and visitors are generally not permitted entry, though the ruins of Plymouth can be from Garibaldi Hill in Isles Bay. While the volcano has been relatively quite since the early 2010's, it still continues to be closely monitored by the Montserrat Volcano Observatory, and is the most studied volcano in the world.
The Montserattian flag