Without doubt the most historic lake in Iceland is Thingvallavatn (also spelled Þingvallavatn) which straddles the rift between the American and European continental plates. It’s a gorgeous lake in a gorgeous setting, with towering walls of ancient lava to the west, and wide beds of it to the east. At the south end, geothermal active hot spots spew constant billows of steam, and to the north hints of the Langjökull glacier can be seen on clear days. It’s the largest natural lake in Iceland, and the site of the original Althing parliament gatherings which began in the 10th century. There are extensive and well-worn walking paths around it, as well as horse trails and diving for the more adventurous.
Mývatn, in the north, is another jewel in Iceland’s crown. it’s fairly shallow, but widely spread out across a lava field and so is edged and dotted with otherworldly lava formations and over fifty islands and islets hosting small, ancient calderas. Its name means Midge Lake, and in summertime that’s wholly appropriate, and though they don’t really bite netted hats and insect repellent may be a good idea. It’s been a main stop along the northern travel route since the Settlement Era, and in 1908 a Viking Age Great Hall was excavated on its western flank at Hofstaðir. The whole Mývatn area is so complex and stunning that it’s a must for any visitor to Iceland!
Another must is the world famous Jökulsárlón glacial calving lagoon. This beautiful body of water brimming with newly birthed masses of pure, blue millennia-old ice opens at its south end, releasing its icebergs out to sea. Visitors can either spend their time strolling along the shore, discovering chunks of ice that resemble magical, melting crystals or can take a ride out onto the lagoon and see the house-sized bergs up close. It’s actually a very young phenomena, created when temperatures rose in the early half of the 20th century, causing its source, the Breiðamerkurjökull glacier, to begin to melt and recede, but though young is exceedingly lovely to behold.
Just at the edge of Icleand’s highlands are a number of excellent fishing lakes, including the Veiðivötn series (literally “Fishing Lakes”) and the nearby Thórisvatn (or Þórisvatn) which has the honor of being the largest in Iceland, though actually a reservoir, dammed at its southern end. The 50 or so lakes in the Veiðivötn area are internationally recognized for their exceptional brown trout, originally of sea trout stock but having adapted to fresh water life since the end of the last Ice Age ten thousand years ago. The waters they swim in may at times have the milky color of glacial runoff, but they are as pure as can possibly be!
Öskjuvatn in the northern highlands and Kerið in the southern plains are both examples of water-filled calderas. Almost perfectly circular, they’re both shored with high, steep and gravelly sides that gorgeously frame the turquoise blue waters inside. Öskjuvatn has recently shown signs of volcanic activity nearby in the form of tremor-induced landslides, and is considered unsafe for most visitors now. Kerið, however, is just off the Golden Circle route, and has a nice path along one edge for that perfect photo opportunity.
No list of Icelandic lakes would be complete without mentioning Lagarfljót in the east. Ten times as long as it is wide, its basin is a deep glacial-carved valley that a river of the same name flows through. It’s the third largest lake in the country and on eastern bank sits Egilsstaðir, a town that has grown twenty times in size in just the last century, and is now a stopping place for nearly everyone traveling in the east. Local history tells of a serpent, or “worm”, that lives in the deeps of the lake, and since the 14th century has, like Irish Nessie, made mysterious show of its presence.