The Þjórsá is Iceland's longest and mightiest river, and its valley -- Þjórsárdalur -- holds what is believed to be the world's most voluminous lava flow since the end of the last Ice Age. The flow is about 8,000 years old, and covers around 805 sq. km (499 sq. miles). In the river's lower reaches, the lava has yielded to fertile grazing land. The upper reaches near Hekla remain bleak, thanks to ash fallout from Hekla's periodic eruptions.
Best Places to Go in 2024 The Best of the Caribbean The Best of Mexico Cruise Inspiration: Top Picks All Destinations »
California Road Trip Guides The Best of the Caribbean The Best of Mexico Cruise Inspiration: Top Picks All Trip Ideas »
Deals & Bookings
Tips & News
How to Craft the Perfect Itinerary for Any Destination
Air Travel Credit Cards & Loyalty Points Cruise News Entry Requirements & Customs Car, Bus, Rail News Money & FeesFAQs Store All Tips & News »