Priorat is easiest by car from Reus, Tarragona or Barcelona. Reus is the nearest natural gateway, and Falset is the region's main town for services.
There are rail services to Falset-Marça on the Barcelona-Tarragona-Zaragoza line, but public transport is limited once you are inside the comarca. If you want wineries, villages and viewpoints in one day, rent a car or arrange a driver.