A picnic table (or picnic bench) is a table with benches (often attached), designed for working with and for outdoor dining. The term is often specifically associated with rectangular tables having an A-frame structure. Such tables may be referred to as "picnic tables" even when used exclusively indoors. Various types of tables have been used for outdoor dining throughout history, but the classic A-frame rectangular picnic table emerged in the United States in the early 20th century. The earliest similar table was described in 1903 and was based on the 18th-century sawbuck table; the most common modern design, known in initially as a "Lassen table", was first used in 1926. While the original and most common material for picnic tables is wooden boards, they may be made anything from split logs to concrete to recycled HDPE plastic. The frame, benches and platform may also be made of different materials. Picnic tables are made in various shapes, from circles to hexagons, and in a wide range of sizes. Traditional picnic tables often pose challenges for accessibility, especially for wheelchair users, but various designs for accessible picnic tables also exist. The typically simple and informal design of picnic tables makes them popular amenities in parks and other public places. They are used for a wide range of dining, educational, recreational and community-building purposes. Their popularity has various impacts on the flora, fauna and soil around picnic table sites, where they often attract various species interested in feeding on human food. Picnic tables are also common targets of vandalism. History Picnic tables emerged from the Victorian tradition of picnics, which often involved either simply spreading a blanket on the ground, or bringing the whole apparatus of indoor dining to the outdoors. This early approach to picnicking suffered the drawback that indoor dining furniture could not be carried far from the home and was often unsuited to outdoor use. The first known modern picnic table was documented in a 1903 patent application by Charles H. Nielsen of Kreischerville, New York. Nielsen's table was designed to be portable and collapsible, so that picnickers could carry it wherever they wished. While the Nielsen table design derived its leg structure from the 18th-century sawbuck table, its built-in seating was innovative. With the rise of US national parks and forests in the early 20th century, the use of fixed picnic tables as a park amenity became increasingly common.