There are five dams on the Douro River functioning to make
the flow of water uniform, generate hydroelectric power, and allow navigation.
Ships with a maximum length of 272 feet and width of 37 feet can pass through the five locks.
The highest lock on Carrapatelo dam has a maximum lift of 115 feet.
There are 39 pictures included here, which might seem like overkill,
but each lock was quite different and the experience was very entertaining.