Place
State highway in King County, Washington, US
State Route 523 is a short Washington state highway located on the city limits of Seattle, Shoreline, and Lake Forest Park in King County. The road itself runs 2.45 miles (3.94 km) east from SR 99 past Interstate 5 (I-5) and ends at SR 522; the highway was first established in 1991, but the roadway from I-5 to 5th Avenue Northeast was once the northern section of Secondary State Highway 1J from 1937 until 1964 and later SR 513 from 1964 until 1991.