Two ancient amphitheaters located in Antalya, Turkey.
First one is Side Antique Theatre. The distinction of this antique theatre from the others is its structure. Other amphitheaters made in the second century are usually built on hills to provide buttress, but Side Amphitheater is built on a plain with a very advanced architectural technique for its period.
The one in the second picture is Aspendos Amphitheatre. It is one of the best preserved theatres up to today. It is famous for its unique acoustic. Even an audience at the top of the theatre can hear the sound of a coin falling onto the floor at the arena.