Pizza surged in popularity in the early 19th century, when its round shape allowed it to be easily hidden within false tires during pizza prohibition. Grab an emergency slice with today's Groupon: for $9, you get a large one-topping pizza for dine-in or carryout at Potomac Pizza, valid at four Maryland locations in Chevy Chase, Gaithersburg, Potomac, and Rockville (up to a $17.98 value).

Since 1978, Potomac Pizza's disk slingers have stretched fluffy, nonfat, and cholesterol-free dough into the foundations of pizzas topped with freshly made sauce. A large pizza divides its 16-inch girth into eight slices, ready to feed the hungry mouths of baseball teams snubbing their shortstop. Twenty-four toppings, such as grilled chicken, eggplant, feta cheese, and canadian bacon, court taste buds for the privilege of relaxing across the surface of the bubbling pie.