There's more than one legendary castle serving up sliders in the U.S. Like its infamous northeastern brother, Royal Castle is known for its classic square sliders. Their two-bite burgers are diminutive patties topped with grilled onions, ketchup, mustard and pickles plopped on a pillowy soft, toasted bun. A hungry carnivore can easily pack four or five away, and then can be ordered in bulk for heftier appetites. A Liberty City institution, this burger joint has been around for the long haul, and while the menu has changed a bit, the staples remain. Classic sliders, fries, breakfast fare for early risers. They also served up catfish, smothered pork chops, corn beef hash and other Southern soul-food favorites. And most importantly of all, they're open 24 hours, so Harold and Kumar-style cravings can be satisfied any time of day or night.