Castries is the capital of the island nation of St. Lucia, in the Caribbean Sea. It’s known for palm-lined Vigie Beach and as a port of call for cruise lines, with duty-free shopping near the harbor. The Cathedral Basilica of the Immaculate Conception, with its colorful murals, sits by leafy Derek Walcott Square park. Lively Castries Market is nearby. In the south, Morne Fortune hill offers views of the city.