The capital city of Puerto Rico is San Juan. Founded in 1521, it is one of the oldest cities in the Americas. San Juan serves as a cultural and economic hub for the island, known for its rich history, colonial architecture, and vibrant arts scene. The city features landmarks such as El Morro, a historic fortress, and the colorful streets of Old San Juan, which attract many tourists. Additionally, San Juan is an important port and serves as the main channel for trade and transportation in and out of Puerto Rico.