Old San Juan's venerated cathedral is Puerto Rico's grandest religious building, and one of its most important. In fact, San Juan Bautista is the seat of the Archdiocese of Puerto Rico. It's also the second oldest church in the Western Hemisphere, and the oldest church on U.S. soil. The history of the church dates to 1521 and the earliest beginnings of the Spanish colonization of the island. The building you see today wasn't the original church, which was demolished by a hurricane. The current structure dates to 1540.
Even then, the elegant gothic facade that you see today evolved over centuries.
The cathedral has also been through its share of trials and tribulations. Over time it's succumbed to numerous robberies and pillaging, most notably in 1598, when troops under the Earl of Cumberland (who famously launched the only successful attack on El Morro) sacked the city and looted the church. It's also had its share of weather-related wear and tear, especially in 1615, when a second hurricane came along and took off its roof.