Only recently part of the main walls around Trujillo are made accessible for the public. From 1o.30 till 18.00 hours (the ones that close the fence of the graveyard are the ones closing this fence as well), you can make a short walk on the city walls, with amazing views, both to the surrounding country side, as well as into the old town.
By the way, for graveyard lovers: Trujillo’s graveyard is worth a visit.