Armed with a flashlight and the full moon’s brilliance, fearless trekkers can explore the tombstones and catacombs with Green-Wood historian Jeff Richman. Those inclined to believe in ghosts should look out for the spirits of cemetery residents such as Boss Tweed, Louis Comfort Tiffany, Leonard Bernstein and Jean-Michel Basquiat. The skeptical can merely enjoy the frisson of nighttime skulking. Flashlight trekkers will be accompanied by live accordion music. Click here for more information and to purchase tickets.