Pioneer Courthouse
Pioneer Courthouse, once known as the Old Post Office Building, is located between SW Morrison Street and SW Yamhill Street, between SW 5th Avenue and SW 6th Avenue. It was designed by M. A. R. Mullet and built in 1875 to house a post office and the United States District Court. It is the oldest federal building west of the Mississippi. Pioneer Courthouse Square, a public square a block west of the courthouse, is named after the building.