Though not exactly at the west–east midpoint of the city, Charles Street is the dividing line between the west and east sides of Baltimore. On any street that crosses Charles Street, address numbers start from the unit block on either side, and the streets are identified as either "West" or "East," depending on whether they are to the west or east of Charles. (The "West" and "East" designations also apply to streets that do not cross Charles Street, but exist on both sides of it.) The entire length of Charles Street is a National Scenic Byway known as Baltimore's Historic Charles Street.