Costa Rica's capital, and largest city, is San Jose, located in the center of the country on a mountain plateau that's commonly refered to as "the central valley." At nearly four thousand feet above sea level, the temperatures in greater San Jose are much cooler and temperate than the beach areas.

San Jose is not known for being particularly picturesque, nor easy to traverse. With a population of the greater San Jose area reaching past two and a half million inhabitants, air quality is relatively poor and traffic is often a real obstacle to touring San Jose. Lamentably, San Jose is often referred to as the "necessary evil" that must be entered in order to cross through the country itself, or to acquire certain goods and services that aren't available anywhere else in Costa Rica.

However, San Jose is still extremely popular with tourists, offering a large number of luxury hotels, casinos, and delightful bed and breakfast inns that pride themselves on creating an oasis in the ocean of concrete that is San Jose. There are a number of lovely museums, historical parks, malls, and art galleries in San Jose, the Central Market and pedestrian boulevard is a popular inexpensive sea of merchandise, and arranging tours to anywhere in the country is extremely easy from any hotel, B&B or one of the hundreds of travel agencies dotting the city. Views from the outlying Escazu and Heredia, nestled opposite each other on the mountainsides cradling San Jose can be magnificent, with the sea of lights of greater San Jose twinkling below.

Nightlife in San Jose revolves around the adult industry, and some sort of red-light district exists in nearly every corner of the city. "Gringo Gulch" is in the center of town, the most famous of these districts, a strip of bars, clubs, and casinos that are packed every night of the week, and hopping with women, gambling, drinking, live music, and lots of partying. A must-visit area for those who really want to see the wild side of Costa Rica's nightlife. The eastern side of San Jose is home to the University of Costa Rica, and in that district there's live music, house parties, concerts, and live venues that pack in the crowds every weekend. El Pueblo is a consortium of over fifty bars, restaurants, discos, and shops that lies just north of Barrio Amon in an architecturally quaint area of San Jose, open from nine until dawn and an extremely popular place for dancing and dining in San Jose.

Although prostitution is perfectly legal and in Costa Rica, with the country holding relatively liberal and casual attitudes toward consentual sex, child prostitution is severely punished in Costa Rica, to the full extent of the law. Most any hotel, casino, or B&B will frown upon guests bringing prostitutes into their establishment, if not prohibit the practice, and it is not unusual in the least for bars, casinos, clubs, and hotels to protect themselves from the harsh and strict law enforcement regarding trafficking of minors by verifying the identification of women who wish to enter.

Petty crime such as pickpocketing is very common in San Jose, and more serious crimes such as muggings, carjackings, and assaults are on the rise.