Sengaiwa (One thousand) Rock and Inuiwa (Dog) Rock are huge rocks located in Inuwaka, Choshi City, Chiba Pref. Legend has it that when Minamoto no Yoshitsune was pursued by his brother, Yoritomo, and was fleeing to Oshu (present-day Tohoku region), he hid himself and 1,000 soldiers and horses in this Sengaiwa Rock. And his dog, left alone on the beach, kept searching for its master and howling for seven days and nights until finally it turned into Inuiwa Rock. There are a lot more legends pertaining to Yoshitsune in the city of Choshi. “Inubo (dog’s howling)” of Cape Inubo, which is located on the opposite side of the peninsula, is said to have come from the story that the dog’s howling was heard even at such a far way place. Kura-hashi and Sasamaki-bashi are the bridges that are believed to have been crossed by the Yoshitsune’s forces. Sengaiwa Rock is famous for the wintering place of sea birds. The rock was formed in the oldest geologic age in the prefecture and is designated as a prefecture’s Natural Monument.