They are nights in which some of the Magic Kingdom's most popular attractions stay open three hours past park closing for Resort Guests who purchase tickets for the even (for $10). The rides open do vary a bit, but they generally include Splash Mountain, Big Thunder Mountain Railroad, the Country Bear Jamboree, The Haunted Mansion, the Tomorrowland Transit Authority, Space Mountain, Buzz Lightyear's Space Ranger Spin, the Astro Orbiter, and Alien Encounter. If one of those are closed, Timekeeper, the Indy Raceway, Pirates of the Caribbean, and the Magic Carpets of Aladdin have been know to open as a replacement. Few people know this, but they play Fantasy in the Sky at the end of E-Ride Nights (most people don't stay). Something about having the park to yourself for fireworks that I love! This is limited to 5000 guests, so the lines are at most 5 minutes, usually walk-on.