Polvorín de Miraflores - Credit: Wikimedia Commons
The Polvorín de Miraflores is an 18th-century structure in San Juan, Puerto Rico, specifically in the island of Miraflores, that served as an ammunition storage place for the Spanish military. The site was included in the National Register of Historic Places in 1984 for its historic importance. Read more on Wikipedia
Source: en.wikipedia.org