Serralles Castle is the prior estate of the wealthy Serralles family, which were a sugar industry barons and the owners of Don Q rum. The house is not so much a castle as a large Spanish-Revival style home, but due to its size and expense is referred to as a castle.
The house was designed by Puerto Rican architect Don Pedro Adolfo de Castro and Besosa and built in the 1930's. Inside, you can see many original details of the house including original furniture and paintings. The surrounding grounds contain sculptured bushes and gardens as well as a reflection pool. From the terrace on the roof, you can get great views of the city. It also has a museum, a cafe, and a theater.
Serralles Castle is located in the city of Ponce across the street from Vigia Cross. Tickets are required to tour the house and the gardens and you can either get tickets just for Serralles Castle or you can also get tickets that allow you to tour Vigia Cross. Tours are available Thursday through Sunday from 9:30am to 5:30pm and you can call 787-259-1774 to confirm operating hours or get additional information. The facilties can be rented out for special occassions, so it is best to call to confirm operating hours. You can view the official website, in Spanish, at http://www.castilloserralles.org/.