San Juan's history is world history, because this small city was for centuries the root of the Spanish Empire in the Caribbean. In the late 1400s, Old San Juan, a deserted outcrop off the larger island of Puerto Rico, was nothing but rocky cliffs rising from the ocean. The Spanish Conquistadores, having failed to establish a Spanish city in the island's lower regions—malaria and Taino attacks thwarted them—retreated to this desolate spot around 1521. It was christened Puerto Rico (rich port) on the island of San Juan—but not long after, a cartographer's error switched the names on a map, and the island became known as Puerto Rico, and the small burgeoning city became San Juan. The Spanish Empire took firm hold of its new asset, quickly building itself defensive forts, a Catholic Church and a cathedral. San Juan was the most important outpost in the Caribbean for centuries—a critical stop on the Gold Route used by Spain to ship the treasures it found in Latin America back home to Europe. Spanish emissaries, judges and governors ruled the Colonial Empire from San Juan, which functioned as part of the government seat through much of the 19th-century. Things underwent a radical change in 1898, when Spain took a fatal tumble in the Spanish-American War. The US annexed Puerto Rico and claimed it as its own territory (later deeming it a "commonwealth"), and San Juan became the capital port. Goods like sugar, coffee, fruit and more poured into the city to be shipped elsewhere, and overnight San Juan mushroomed. It had already outgrown the confines of Old San Juan—marked by 16th-century Spanish walls—and into Condado and Santurce. The growth continued, and San Juan was soon out of control: housing developments sprang up for poor workers, crime was rampant and, ironically, Old San Juan was considered too dangerous for outsiders to venture into. Visitors and the middle-class stayed in Isla Verde and Condado. It wasn't until 1992 that San Juan officials decided another change was needed. As the world got ready to mark the 500-year anniversary of Christopher Columbus's "discovery" of the New World—and Old San Juan was a mess. A major public initiative rehabbed its colonial splendors, encouraged cruise ships to dock in the port, and cleaned up the notorious "La Perla" slum that kept many people from visiting. Now Old San Juan is the city's crown jewel, and the rest of San Juan is thriving.