38°56′37″N77°06′57″W / 38.943548°N 77.115794°W /38.943548; -77.115794TheDalecarlia Tunnel inBrookmont,Maryland, nearWashington, D.C., is a former railroad tunnel that presently carries theCapital Crescent Trail underneath MacArthur Boulevard and theWashington Aqueduct.
It was built in 1910 as part of theGeorgetown Branch of theBaltimore and Ohio Railroad.[1] It is aRoman arch tunnel, measuring 18 feet (5.5 m) wide by 340 feet (100 m) long. It features decorativebrick facings on both ends and is lined with brick throughout its length.
CSX Transportation, the successor to the B&O Railroad, ceased train operations through the tunnel in 1985 and officially abandoned the rail line in 1986.
