Making a crescent around the lagoon and including the Condado (although we treat the Condado separately here) Santurce is the largest and most diverse borough in San Juan.  For gay visitors the majority of the city's gay bars and clubs are here off De Diego near Robert Todd, De Diego being a wonderful thoroughfare lined with ancient rainbow eucalyptus trees.  The neighborhood abounds with street art far above the class of amateur graffiti and you can make a day (and a photo album) of the colossal works that loom everywhere.  The market in the Placita near Hippodromo is a wealth of fresh fruits and vegetables by day but on weekend nights this cramped plaza erupts in vibrant revels as young and old crowd into the streets and its many bars and restaurants.  Day or night Santurce is a delightful treat!