Since it opened the doors of its third location at U Square in Clifton, Keystone Bar & Grill has become an instant classic with University of Cincinnati students. Their craft beer selection and extensive macaroni and cheese menu are the stuff of college-kid legends. Inspired by the success, the Keystone team opened the Mac Shack, a retro fast-casual extension to the main restaurant. The Mac Shack offers all nine of Keystone’s classic otherworldly macaroni and cheese dishes — from the Gordon Lightfoot with ham and Swiss to the Fleetwood Mac with pesto, tomato and mozzarella — plus new and inspired daily creations. Bonus add-ons and toppings include locally sourced proteins (chicken, ham, bacon and brisket), crumbled up Flaming Hot Cheetos or Grippo’s, cornbread and healthier options like spinach. The Mac Shack is open until a bleary 4 a.m. on Thursday, Friday and Saturday, for nights of over-indulgence that must end in noodles topped with bacon, caramelized onion and lots of cheese. The Mac Shack, 249 Calhoun St., Clifton Heights, 513-229-9080, eatmacshack.com.