Cockburn's is one of Vila Nova de Gaia's historic port lodges, set a little uphill from the densest riverside tasting strip. Tours usually focus on the working lodge, barrel ageing, coopering traditions, and the long British-Portuguese trade story behind port wine.
It is commercial, of course, but port lodges are one of Gaia's defining travel experiences. Choose it if you want a slightly less riverfront-polished visit, and leave time to walk back down toward the Douro after tasting.