The Golden Circle is Icelands greatest hits reel, and this full-day loop from Reykjavik links the three showstoppers plus a bonus crater. You will stand in the rift valley at Thingvellir where two tectonic plates slowly pull apart, watch the Strokkur geyser fire scalding water skywards every few minutes, and feel the spray off the thunderous two-tier Gullfoss waterfall. The tour finishes at Kerid, a vivid red volcanic crater cradling an emerald lake. Wear sturdy shoes and pack a windproof layer, as the weather here turns on a whim.