Set high on a hill overlooking Ponce is a startling reminder of the height of the city’s flourishing sugar industry, when its port was the busiest on the island. Castillo Serrallés (17 Calle El Vigía, 787/259-1774, 787/259-1775, or 800/981-2275, fax 787/259-3463, castserr [at] coqui [dot] net, www.castilloserralles.org, Tues.– Thurs. 9:30 a.m.–5 p.m., Fri.–Sun. 9:30 a.m.– 5:30 p.m., gardens $2, $1 students and seniors; gardens and castle $5, $2.50 students and seniors) was built in 1934 for Eugenio Serrallés, a leader in the local sugarcane industry and founder of the still-operating Serrallés Rum Distillery, maker of the island’s premier rum, Don Q.

Designed by architect Pedro Adolfo de Castro, the four-story Spanish Moroccan–style mansion was last inhabited in 1979 by Serrallés’s daughter. It became a museum in 1991.

Castillo Serrallés contains many of the Serrallés family’s original furnishings, many of them made by Puerto Rican craftsman or imported from Europe, the oldest piece being a small 16th-century table in the foyer. No cost was spared in the construction of the house. The parquet wood floor in the parlor was imported from Brazil, and the dining room, which took 18 months to build, features a painted, hand-carved ceiling made of oak, mahogany, and ceiba woods, and the black-and-cream bathrooms are designed in an art deco style.

The building was technologically advanced for the times: It even has an intercom system with 14 receivers as well as an elevator. In the kitchen is a 1929 GE side-by-side refrigerator that still works. One room in the house has been converted into an exhibition space that explains and illustrates sugarcane processing and rum-making.