Pennsylvania Route 340 (PA 340) is a 30-mile-long (48 km) state highway located in Lancaster and Chester counties in Pennsylvania. The western terminus is at PA 462 in Lancaster. The eastern terminus is at U.S. Route 30 Business in Thorndale. The route is a two-lane road passing through rural areas, heading through the Pennsylvania Dutch Country in eastern Lancaster County that is home to several Amish families and rural areas in western Chester County, serving the communities of Bird-in-Hand, Intercourse, White Horse, Compass, and Wagontown. PA 340 intersects US 30 near Lancaster, PA 772 in Intercourse, PA 897 in White Horse, PA 10 in Compass, PA 82 near Coatesville, and US 30 again near Thorndale.

Chester County, colloquially referred to as Chesco, is a county in the Commonwealth of Pennsylvania. It is located in the Delaware Valley region, located in the southeastern part of the state. As of the 2020 census, the population was 545,823(As of 2022), increasing by 7.1% from 498,886 in 2010. The county seat is the Borough of West Chester. The most populous of its 73 municipalities is Tredyffrin Township. The most populous boroughs are West Chester and Phoenixville. Coatesville is the only municipality in the County organized under the City form of government, a technical rather than demographic distinction. Chester County was one of the three original Pennsylvania counties created by William Penn in 1682. It was named for Chester, England. The county is part of the Southeast Pennsylvania region of the state.