The historic centre of Arcidosso, one of the most striking in Amiata, develops in a long pyramid shape along the plateau dominated by the castle. Only three gates of the old medieval walls remain, of which two are original – the Porta di Castello, and the Porta Talassese which faces towards the sea. From here, going down towards Codaccio, is the Porta dell’Orologio, built in 1851 to replace the Porta di Mezzo.