Fodor's Expert Review Valahnúkur

This mountain was formed in a single geologic event, and while exploring this magical stretch of coastline, you can see evidence of the different phases of the eruption. Tuff forms during an explosive eruption, and pillow lava forms when lava flows underwater. Out on the sea, you can see majestic black cliffs that serve as castles for birds. A bit farther out you can see the famous Eldey Island, where the great auk (a now-extinct species of bird) used to live. The auks survived the longest in Iceland, but the last great auk was killed on June 3, 1844 for a Danish natural history collector. Eldey is now a bird sanctuary. To reach Valhnúkur, take the road that leads off Route 425 through lava fields. Turn right (the turn is marked, "Reykjanesviti"), at the T-intersection, and then go 900 meters on an unpaved road, past the impressive Reykjanesviti lighthouse. On the way back, take the left branch at the T-intersection, and in 500 meters you'll reach Gunnuhver, Iceland's biggest mud pool.