The district of El Arenal borders on the Guadalquivir river, guarded by the impressive tower "Torre del Oro". It was once a quarter with ammunition workshops, storage houses and wharfs. In the early 17th century there was a big flood and the river turned the surrounding area into mud. During this time El Arenal became a notorious part of the underworld. In the 20th century the river was dug out and made into a canal. In 1992 the Expo was constructed on the other side of the river. Many bars and bodegas can be found today in the small side streets surrounding the bullring and the opera. Boat excursions, as well as bus excursions start from the Torre del Oro. The wonderful promenade which leads along the river has great views over to the districts of Triana and La Cartuja on the other side of the river.