oorspronkelijk gebruikt om port over de Douro naar Porto te transporteren Português: Rabelos no rioDouro com a cidade do Porto ao fundo, Vila Nova de Gaia
described at URL: https://www.flickr.com/photos/gaetanlee/315911158/ operator: Flickr URL: https://live.staticflickr.com/104/315911158_eef3daa378_o.jpg determination
Flickr user ID: 63488671@N00 publication date: 5 December 2014 operator: Flickr described at URL: https://www.flickr.com/photos/chilangoco/15768880447/