It might not be in the best condition, but it's a must see because it's one of the second oldest churches in the caribbean. plus, it hold the burial remains of Juan Ponce de Leon, who was seeking endlessly for the fountain of youth and who was puerto rico's first governor.
BONUS: The plaza where the church is located is one of the prettiest in all of old san juan, and there are beautiful places to stroll and Rosa de Triana (nearby restaurant) has flamenco show nightly friday through sunday that's free!
If you're planning to visit Old San Juan, don't miss the second-oldest cathedral in the Americas, the Cathedral of San Juan Bautista. It has a pretty facade in the late Gothic style overlooking a very nice plaza. The Cathedral holds the remains of Ponce De Leon, the first Governor of Puerto Rico who as the story goes, died while searching for the fountain of youth in Florida. It's worthwhile finding a time to visit the inside, but if not you should at least stroll by on a walk through Old San Juan.
This is not the most elaborate cathedral in Latin America, but its subtleness is elegant. It blends with the city, rather than sticks out.
The statues in the cathedral are brightly colored. Take a look inside the cathedral to find tomb of the island's first governor Juan Ponce de León and the relic of the roman martyr, San Pio.