The historic center preserves its Roman arena, medieval walls and bridges, Piazza delle Erbe and Piazza dei Signori with their surrounding palazzi, the Castelvecchio fortress, and numerous churches, forming a largely intact layered townscape of Roman, medieval, and Renaissance fabric. It is administered by the municipality of Verona as a World Heritage Site. The historic center is freely accessible as a living city, with individual monuments such as the arena and Castelvecchio open on a ticketed basis.