6 Best Sights in Ponce and the Porta Caribe, Puerto Rico

Built by Salvador de Vives in 1838, this was one of the area's largest coffee plantations. It's a technological marvel: water from the nearby Río Canas was funneled into narrow brick channels that could be diverted to perform any number of tasks, like turning the waterwheel. (Seeing the two-story wheel slowly begin to turn is fascinating, especially for kids.) Nearby is the two-story manor house, with a kitchen dominated by a massive hearth and furniture that hints at life on a coffee plantation nearly 150 years ago. In 1987, the plantation was restored by the Puerto Rican Conservation Trust, which leads several tours each day (at least one in English; by reservation only, call several days in advance or reserve online). A gift shop sells coffee beans and other souvenirs. Allow an hour's drive on the winding road from Ponce.

In Coamo you can take a dip at the famous Piscinas Aguas Termales, the thermal springs said to have curative powers. There's a changing room at the end of a path. Note that parking is somewhat limited here, especially on weekends, when the attraction is visited by locals from all over the island. There's a gift shop with everything you need to enjoy the pools and bring memories home.

This lovely Spanish-style villa—so massive that townspeople dubbed it a castle—was built in the 1930s for Ponce's wealthiest family, the makers of Don Q rum. Guided tours provide a glimpse into the lifestyle of a sugar baron, and a permanent exhibit explains the area's sugarcane and rum industries. Highlights include the dining room, with original hand-carved furnishings, and the extensive garden, with sculptured bushes and a shimmering reflection pool. A large cross looming over the house is an observatory; from the top, you can see the Caribbean.

Designed by Edward Durell Stone, who also designed the original Museum of Modern Art in New York City and the Kennedy Center in Washington, D.C., Ponce's art museum is easily identified by the hexagonal galleries on its second story. It has one of the best art collections in Puerto Rico, which is why residents of San Juan frequently make the trip. The 4,500-piece collection includes works by famous Puerto Rican artists such as Francisco Oller, represented by a lovely landscape called Hacienda Aurora. European works include paintings by Peter Paul Rubens and Thomas Gainsborough, as well as pre-Raphaelite paintings, particularly the mesmerizing Flaming June, by Frederick Leighton, which has become the museum's unofficial symbol. The museum also offers special exhibits, three sculpture gardens, and a café.

In a city filled with neoclassical confections, this is one of the most elaborate. Alfredo B. Wiechers, who returned to his native Ponce after studying architecture in Paris, designed the house. Though small in scale compared with some of its neighbors, it makes a big impression with details like huge arched windows and a massive rooftop gazebo. No wonder that soon after it was completed in 1911 the Villaronga-Mercado family decided to make it their own. Check out the stained-glass windows and other fanciful touches. The house, restored by the Institute of Puerto Rican Culture, now operates as the Museum of Puerto Rican Architecture, so, in addition to original furnishings, you'll find exhibits on Wiechers and other Ponce architects of his era.

After El Morro in Old San Juan, this distinctive red-and-black-striped building may be the second-most-photographed structure in Puerto Rico. Built in 1882 as a pavilion for an agricultural and industrial fair, it was converted the following year into a firehouse. In 1990, it took on new life as a small museum tracing the history—and glorious feats—of Ponce's fire brigade. Kids love the antique fire truck on the lower level. Short tours in English and Spanish are given on the hour starting at 10; if the trolley is running, you can sign up for free tours of the historic downtown here, too. Helpful tourism officials staff a small information desk inside.