Route F88 to Askja

Starting from the Ring Road, the first 60km (37 miles) of Route F88 follow the western side of the Jökulsá á Fjöllum -- the same river that forms the canyon in Jökulsárgljúfur National Park further downstream. Just south of the Ring Road and west of Route F88 is Hrossaborg, a 10,000-year-old crater formed when rising magma heated groundwater, prompting a massive explosion of steam and rock. Hrossaborg was once used as a pen for rounding up horses -- thus the name, which means "Horse Castle." A small road leads from Route F88 right into Hrossaborg's natural amphitheater through a collapsed crater wall.

In roughly 40km (25 miles), Route F88 comes to its first major ford at the Grafarlandaá river, known for its pure-tasting water. 20km (12 miles) further south is Herðubreiðarlindir, a lovely highland oasis of moss, wildflowers, and springs gushing from beneath the lava rock to converge on the Lindaá River. Herðubreið, a majestic table mountain, looms 6km (3 3/4 miles) to the west. Herðubreiðarlindir has a mountain hut and summer warden, and is also the launch point for the Öskjuvegurinn, a memorable 5-day trek through some of Iceland's starkest wastelands. (Most of the route traverses the Ódáðahraun, which translates to "Lava Field of Evil Deeds.") The Öskjuvegurinn skirts Herðubreið, and reaches Askja's Drekagil hut on the second night. For further details on all the huts along the route, contact Ferðafélag Akureyrar. A 5-minute trail leads from Herðubreiðarlindir to the remains of a tiny underground shelter, where Fjalla-Eyvindur -- Iceland's most legendary outlaw -- reportedly survived the winter of 1774-75 on a diet of dried horsemeat and angelica roots. The original shelter collapsed and was renovated in 1922. A map available at the hut outlines other short, pleasant hikes in the Herðubreiðarlindir area.

In clear weather, the view of Herðubreið is awe-inspiring. In 2002 a national poll was conducted to determine "Iceland's favorite mountain," and Herðubreið was the overwhelming winner. Its name means "Broad Shoulders," and its flattened top is the result of eruptions beneath the crushing weight of a glacier. With its steep screes and vertical cliff faces, Herðubreið is a very challenging and somewhat dangerous climb. If you do make the attempt, consult the warden at Herðubreiðarlindir first, and allow 12 hours round-trip.

Askja

In Iceland's recorded history, no cataclysm produced more ash than the 1875 volcanic eruption at Askja, which means "Caldera" in Icelandic. The ash blanketed 10,000 sq. km (3861 sq. miles) of land, killing livestock and forcing hundreds of Icelandic farmers to emigrate to North America. Askja -- designated a stratovolcano because of its layers of lava from periodic eruptions -- erupted most recently in 1961, but most of the current topography took form in 1875. Askja is also Iceland's most dramatic illustration of a subsidence cauldron, formed when underground passageways of molten rock empty and collapse, leaving an enormous bowl at the center of the volcanic edifice. Askja's collapsed center, dominated by Öskjuvatn Lake, is 8km (5 miles) wide and still sinking. Öskjuvatn is Iceland's deepest lake, at 220m (722 ft.).

The mountain hut closest to Askja is at Drekagil gorge, 35km (22 miles) from Herðubreiðarlindir. From Drekagil, Route F894 extends 8km (5 miles) to Vikraborgir, a crater row formed during the 1961 eruption. Tour buses park at Vikraborgir for the easy 35-minute walk south to Víti, a lake-filled crater formed in 1875 and separated from Öskjuvatn by a narrow ridge. (Víti, by the way, means "Hell.") The Icelanders are usually the least hesitant to scoot down Víti's steep walls and plunge into the warm, opaque, eggy-smelling water, which reaches a depth of 60m (197 ft.). The water temperature ranges from 72°F to 86°F (22°C-30°C) -- a bit tepid at times, but it's warmer if you swim out to the middle. You can also dig your toes into the hot mud on the lake floor, but be careful not to get burned. Trails proceeding from Víti around Öskjuvatn are often blocked by signs prohibiting access, so check with the warden at Drekagil before setting out.

A longer, more suspenseful approach to Víti starts at the Drekagil hut and proceeds through Dyngjufjöll, bypassing Vikraborgir. Consult the warden on the status of the trail, and allow 3 hours each way. A stroll up the Drekagil gorge is also worthwhile.

Kverkfjöll

The Kverkfjöll volcanic system -- which reaches 1,936m (6,352 ft.) in height and extends 10km (6 miles) on a south-to-north axis -- is mostly buried beneath Vatnajökull, but its northern rim protrudes from the glacier's edge. With so much geothermal activity churning beneath Europe's largest mass of ice, Kverkfjöll is usually characterized as a collision of natural extremes. Yet the most lasting impressions are of its austere and solemn beauty: the mesmerizing pattern inside an ice cave, perhaps, or a view over reddish-black wastes with the barest etching of pale grey lichen.

The most common tourist mistakes are to wear jeans, a real encumbrance in the rain, or sneakers, which shred on lava trails and soak through in snow or mud. Also remember to bring a water bottle, as it can be difficult to find drinking water free of silt.

Hiking Routes -- The wardens at Sigurðarskáli, the only mountain hut in the Kverkfjöll vicinity, sell hiking maps and dispense excellent advice.

From Sigurðarskáli, a well-marked manageable trail leads up Virkisfell for fabulous views; allow at least 90 minutes round-trip. From the mountain, the trail continues past several volcanic fissures to Hveragil, a river gorge and oasis of vegetation nurtured by hot springs; a marvelous natural bathing pool is fed by a waterfall. Hveragil is 12km (7 1/2 miles) from Sigurðarskáli, and the round-trip hike takes around 7 hours. A rough Jeep track extends to Hveragil from Route F903, but talk to a warden before braving it.

A road extends 4km (2 1/2 miles) from the hut to the edge of the Kverkjökull glacial tongue; a more direct walking trail is only 3km (2 miles). From the end of the road, it's a 10-minute walk west to where a river emerges from a spectacular ice cave (íshellir) at the edge of the glacier. The play of light on the sculpted hollows and undulating walls is utterly entrancing. Eerie crashing sounds emanate from deep within the cave, and venturing inside is very dangerous. The escaping river is warmer in winter, when hot springs are less diluted by glacial meltoff.

All unguided hikes on the glacier are discouraged, but if you do go, be sure to tell the wardens where you're headed and stick to established trails.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.