The Teatro Olimpico (Olympic Theatre) is a theatre in Vicenza, northern Italy, and considered one of the first covered theatres. It was opened in 1585 with a performance of Sophocles' Oedipus Rex. The original set design for this performance still exists in the theatre today! It is a beautiful trompe- l'œil of the streets of Thebes receding into the distance, and is the oldest surviving stage set still in existence. The theatre still puts on plays and musical performances, but audience sizes are limited to 400 for conservation reasons. It is not equipped with heating or air conditioning, which could damage the delicate wooden structures. Stepping into the theatre is stepping back in time – the architect drew inspiration from antiquity. Since 1994, the Teatro Olimpico has been included in the UNESCO World Heritage Site list.