When you are in Porto, a great way to see the Port wine area in Vila Nova de Gaia is to take the cable car from the top of the town down to Cais de Gaia, on the river bank.
The Teleférico de Gaia was built between March 2009 and April 2011. The upper station puts you close to the Metro station, where you can either take a tram across the river to the historic sites of Porto city centre, or you can walk across the bridge for some breathtaking photo opportunities.
The cable car costs €5 per adult for a one-way trip, or you can buy a family ticket for €20. See the official Teleférico de Gaia website for more information and a great photo gallery.