Kauai is geologically the oldest of the main Hawaiian Islands. Kauaʻi's origins are volcanic, the island having been formed by the passage of the Pacific plate over the Hawaii hotspot. At approximately six million years old, it is the oldest of the main islands. The highest peak on this mountainous island is Kawaikini at 5,243 feet (1,598 m). The high annual rainfall has eroded deep valleys in the central mountains, carving out canyons with many scenic waterfalls. The Na Pali Coast is a center for recreation in a wild setting, including kayaking past the beaches, or hiking on the trail along the coastal cliffs.