Golden Circle Afternoon: Kerid, the Crater That Collapsed Rather Than Exploded

Six hours in the afternoon, in a minibus with Wi-Fi on board, back in Reykjavík around 18:00. Þingvellir first: the Eurasian and North American plates are separating here, and the Alþingi, founded on this ground in 930, is the oldest parliament still in existence anywhere. At Geysir, Strokkur goes every 8 to 10 minutes, sending water between 25 and 40 metres up. Gullfoss drops 32 metres in two stages, and it is the waterfall more people visit than any other in the country. Kerið is the one worth understanding rather than just photographing. It formed over 6,500 years ago, and not the way most craters do: a cone-shaped volcano collapsed in on itself, and the hollow left behind filled with water over time. The caldera is 270 metres across with walls up to 55 metres high, and the lake at the bottom is blue-green against red volcanic rock. A loop path runs around the lake and takes about 20 minutes. In summer the red rock sits against green moss. In winter the slopes are under snow and the lake freezes. The group stays small, and the guide travels with it.