Honolulu is on the south shore of Oahu; it dominates the island, and the city's government administers all of Oahu. The island itself is a volcanic mass divided into sections by two separate mountain ranges. Both ranges run northwest to southeast: the Waianae Range on the western side of the island, and the Koolau Range to the east. The Koolau separates the city of Honolulu and its hotel-choked neighborhood of Waikiki from the windward side of the island and the towns of Kailua and Kaneohe. Travelers can take one of three tunnels — Pali, Likelike or the H-3 freeway — to cross from one side to the other. Between the two mountain ranges is a central plain.