Original: The Douro valley where Port wine is produced was defined and established as a protected region , or appellation in 1756 -- making it the third oldest defined and protected wine region in the world after Tokaji ( 1730 ) and Chianti ( 1716 ) .
Simplified: The Douro valley where Port wine is produced was defined and established as a protected region , or appellation in 1756 . It is the oldest defined and protected wine region in the world .