had one. In New York state's "hop belt" numerous hop barns were constructed between the early 19th century and the beginning of the 20th century. Ostego, Chenango, Madison, Oneida, Montgomery and Schoharie Counties were the primary areas contained within the hop belt. As hops production basically dwindled down to only Washington state, in the U.S., the remaining hop houses elsewhere have begun to disappear. Defunct hop kilns are found in areas where hops production is still ongoing, in Kent, England, for instance. Design The design of hop houses changed significantly over time, as did the area hops were grown in. In New York, for instance, early hop barns were low with some ventilation. Later hop barns evolved into taller, more narrow buildings, often topped with a cupola over the drying kiln area. Later in the history of New York hops production, with farmers focused on more efficient means of production, pyramid shaped barns were built, eventually evolving into multi-pyramid hop barns. Potato barns and houses Barns designed to store potatoes are semi-subterranean (partially below ground) to naturally moderate the indoor temperature like a giant root cellar. The potatoes in storage could not be allowed to freeze or get too warm. Potatoes were not mass-produced until the end of the 19th century and so most old potato barns are 20th-century buildings with concrete walls. Buildings to store sweet potatoes are sometimes called a potato house. Pole barns A pole barn in North America is a barn that is essentially a roof extended over a series of poles. They are generally rectangular and do not require exterior walls. The roof is supported by the poles, which make up the perimeter of the barn. Walls may be added to pole barns but are not required for structural integrity. The roof can be gabled or hooped. Pole barns are often used for hay storage or livestock shelter, and larger structures are also used for indoor horse stables and riding arenas. This type of barn is not only very common in modern agriculture but is also used for other applications where large spaces are needed, including boat and truck storage, warehouses, strip malls, retail stores, public exhibit buildings at a fairgrounds, and related uses. Residential garages are also built as pole barns because of their quick construction time and efficient use of materials. The advantages of pole barns include their low cost and their ability