Grab tickets and join the crowds at a game at Plaza de Toros. If there's nothing on while you're in the area, you might like to check if they offer a tour of the facilities.
This sporting facility is in Laguna de Duero, a place that has so much on offer! Jose Zorilla Stadium, University of Valladolid, and Valladolid Cathedral are other good sightseeing opportunities nearby when you're all done at Plaza de Toros.