Known as the 'The Garden Island', Kauai is an ancient and deeply eroded extinct volcano, rising 5000m (15,250ft) above the sea floor. Separated from Oahu by the angry, open ocean of the Kauai Channel, it was the only island that repelled King Kamehameha's efforts to unite Hawaii and remained self-governing until the 1820s. Kauai regulations state that no building may exceed the height of a coconut tree, preventing development from scarring the breathtaking scenery. There are more sandy beaches than many other islands and nearly 45% of its coastline is virtually deserted. Despite having over 300 surf spots, underwater topography is, allegedly, not as ideal as Oahu. The North Shore high volcanic cliffs hold few spots and the inaccessibility of the Na Pali coast makes it very dangerous to find and ride the few spots that face the brunt of the winter swells.