Bay Parkway was first mapped as 22nd Avenue, now the grid's missing number.
The road was first mapped as 22nd Avenue on Brooklyn's numbered avenue grid, and 22nd Avenue is now the only missing number. Its renaming as a parkway was first proposed in the state legislature in 1892, to make land along it more desirable. Forgotten New York dates the new name to around then, while Wikipedia says it was known as 22nd Avenue until the 1930s.