Sevilla extends on both banks of the Guadalquivir river. On the eastern bank lies the Plaza de toros de la Real Maestranza de Caballerķa de Sevilla, the oldest bullring in Spain. This is an oval arena where corridas are held on a regular basis. In older times the harbour of Sevilla was located here. The Torre del Oro was set up by the Moors in the 13th century to protect the harbour of Sevilla.