If you do nothing but head up to this town's famed Roman Theater and look out over the red-tile roofs of the Rhône Valley, you'll be happy you made the 20-minute trip from Lyon. Vienne is a historian's dream, and every street takes you to yet another ancient church, another austere Roman ruin, or another postcard-perfect view of crumbling walls and sloped roofs.
The Billet Intermusée (€8) admits you to all local monuments and museums within a 48-hour period. Even better, the Billet-Pass (€6) admits you to three museums and the Théâtre Roman. Both are available at the first site that you visit.