Sprawling Reykjavík, the nation's nerve center and government seat, is home to half the island's population. On a bay overlooked by proud Mt. Esja (pronounced eh-shyuh), with its ever-changing hues, Reykjavík presents a colorful sight, its concrete houses painted in light colors and topped by vibrant red, blue, and green roofs. In contrast to the almost treeless countryside, Reykjavík has many tall, native birches, rowans, and willows, as well as imported aspen, pines, and spruces.Reykjavík's name comes from the Icelandic words for smoke, reykur, and bay, vík. In AD 874, Norseman Ingólfur Arnarson saw Iceland rising out of the misty sea and came ashore at a bay eerily shrouded with plumes of steam from nearby hot springs. Today most of the houses in Reykjavík are heated by near-boiling water from the hot springs. Natural heating avoids air pollution; there's no smoke around.