Quadripoint
The Four Corners Monument is the only point in the United States where four states meet: Colorado, Utah, New Mexico, and Arizona meet at right angles. The United States first acquired the area now called Four Corners from Mexico after the Mexican–American War in 1848. In 1863 Congress created Arizona Territory from the western part of New Mexico Territory. The boundary was defined as a line running due south from the southwest corner of Colorado Territory, which had been created in 1861. By defining one boundary as starting at the corner of another Congress ensured the eventual creation of four states meeting at a point, regardless of the inevitable errors of boundary surveying. The monument is centered at .
Seven Corners, Virginia
Seven Corners is a commercial center and census-designated place (CDP) in Fairfax County, Virginia, United States. The population was 9,255 at the 2010 census. Seven Corners has a "Falls Church" mailing address but is not within the independent City of Falls Church, Virginia. The area got its name from the intersection of State Route 7 (Leesburg Pike and East Broad Street), U.S. Route 50 (Arlington Boulevard), State Route 613 (Sleepy Hollow Road), State Route 338 (Hillwood Avenue) and Wilson Boulevard (also part of State Route 613). The junction of these four roads once created seven corners.