The large fortress of Santo Domingo's Zona Colonial, the oldest and original part of the city, is an interesting oasis of tranquility turned inward from the big city. Also called the Fortaleza de Santo Domingo, the fort is bordered by the Ozama River and the cobblestoned Calle de las Damas, the oldest and most historic road in the city. Dating from 1502, the fort is the oldest military complex in the Americas. The peaceful atmosphere is a marked contrast to what it was in its heyday, as from this strategic site Spain launched numerous expeditions to Cuba, Puerto Rico, and the North American mainland. The fort has been tidied up and open to the public since the 1960's. You enter the complex through the dramatic Gate of Carlos III. The admission fee is less than a dollar, although you may be greeted by a tour guide who would like to give you a personal tour of the grounds for an additional fee. As usual, I like to tour a place solo if I can help it. Upon admission, you will get a little pamphlet (in Spanish only) with a nice site map and some historical information.