The Katsura River (桂川, Katsura-gawa) is a continuation of two other rivers, the Hozu River, a small, speedy river which begins in the mountains near Kameoka and then slithers through the mountains separating Kameoka and Kyoto; and the Ōi River (大堰川 Ōi-gawa), which emerges from those mountains and expands into a shallow, slow-flowing river until Togetsukyo Bridge in Arashiyama.