If you make only one foray outside Reykjavík, take this popular trip, offered by many tour operators, to the lakes, waterfalls, and hot springs just inland from the capital. If you take the trip after the spring thaw, it will begin at ?Þingvellir, the ancient seat of the world's oldest continually functioning parliament, before heading on to see the original Geysir hot spring (hence the term geyser) and the famed Gullfoss, the "Golden Waterfall."