The Prison Ship Martyr's Monument is a memorial to the 11,500 American soldiers who died in captivity aboard 16 British prison ships in Wallabout Bay during the American Revolutionary War. The history of the monument is really quite complex, but I'll try to sum it up. Remains of some of the soldiers who died aboard the ships were initially interred near the Brooklyn Navy Yard (Vinegar Hill) in 1808, but moved and re-interred in 1873 beneath a small monument in what is now Fort Greene Park. Funds were then raised for a larger monument designed by Stanford White. The monument is a granite Doric column 149 ft high, and at the top of the column sits an eight-ton bronze brazier (funeral urn) by the sculptor Adolf Weinman.
The monument is rarely opened, but last Sunday it was open to the public and I had the opportunity to go inside for a few minutes and do a quick drawing (I got there just as they were closing it up). Apparently there used to be a spiral staircase leading to the top of the monument and visitors could pay to climb up and see the views of Manhattan, but now there's just a rusty ladder that looks like it might crumble if touched lightly. On the concrete floor there is a copper door leading to the crypt below (the crypt was not open). Unfortunately I was rushed out before I had a chance to draw it.
Fort Greene Park actually used to be Fort Putnam under the supervision of General Nathanael Greene during the Revolutionary War (1776) because it is one of the highest points in Brooklyn. It housed six eighteen-pound cannons and was the largest fort on Long Island. The fort was later renamed after Greene.