San juan is a nice place to visit, but be careful sometimes the locals want to sell you stuff. If you looking for the best cab driver baragin with them on the best deals with other drivers

San Juan is a cool city, but you definitely need to rent a car to see everything worth seeing. Viejo San Juan is the stereotypical tourist area, and it certainly merits your attention, but don't spend too much time there. There's so much to see not only in San Juan, but around it (like El Yunque rainforest), and also throughout the whole island. With a little bit of time and a car you could see lots of neat parts of the whole island, and even swing a visit to one of the smaller islands off the eastern coasts and hit up the bioluminescent bay in Vieques or el Pozo de Jacinto in Isabela. The city of Saint John and the Island of enchantment deserve more than two or three days; a week at the minimum will get you started.