Climbing Esja is formidable but rewarding, and the mountain's main trails are well-marked and negotiable. Several routes lead up Esja, which is more of a volcanic range than a single peak. The recommended and most popular trail starts at a parking area along Route 1. (Heading north from Reykjavík, it's at the base of the mountain; look for the sign "Gönguleiðir á Esju" just after a driveway marked "Mógilsá.") From there it's a 780m (2,559-ft.), 4km (2 1/2-mile) ascent to the marvelous Tþverfellshorn lookout. Allow at least 5 hours for the return trip. The tallest peak (914m/2,999 ft.) is 3km (2 miles) farther along, but only tempts very devoted hikers. The excellent Myndkort "photomap," compiled from aerial satellite photographs, details all of Esja's trail routes.

North of Esja, drivers on Route 1 pass through a very deep, 6km (3 3/4-mile) tunnel beneath Hvalfjörður, completed in 1998. (Beware: It's a speed trap.) On the far side are Iceland's only toll booths, which collect 900kr ($14/£7.20; Visa/MasterCard accepted) per car. The tunnel shortened the thru-route by 47km (29 miles), but the old route around the fjord is a scenic drive and the only way to reach Glymur.

Hvalfjörður means "whale fjord," and, if you keep your eyes fastened on it, you might see why. At 30km (19 miles) it's the longest fjord in southwest Iceland, and was an important naval base for the Allies in WWII.

Translating to "clamor," Glymur is the tallest waterfall in Iceland (200m/656 ft). What Glymur lacks in raw power, it makes up for in lithe beauty. Getting there is half the fun, with great views out to the fjord and surrounding countryside, and into a dramatic gorge filled with nesting birds in late spring and early summer. When the flow is substantial, Glymur is as breathtaking as Gullfoss, but with 99% fewer tourists, thanks to its inaccessibility to cars. Glymur is also relatively unknown because the path is somewhat dangerous: the trail requires real caution, good balance, and agility. Also, the waterfall is less spectacular when the flow tapers off; ask around at local hotels and information centers to get an educated guess based on rain and meltoff.

To reach the trail to Glymur, turn off the main road at the head of Hvalfjörður. The parking area is a few minutes ahead. From the car park, a fenced-off dirt road bears toward the right, but the trail bears slightly left, marked with yellow-painted stones. In 2 to 3 minutes the trail divides, again without posted signs, though both routes are still marked with yellow rocks. The trail bearing left takes you up the west side of the gorge. This trail is shorter and easier but you don't get a good view of the waterfall. The right-hand path takes you across the river and up the east side of the gorge and is fully worth the extra effort. It reaches the river in 20 minutes or so; you have to wind through a cavity in the cliff to reach the shore, and then cross the river on a round wooden beam, while holding on to a steel suspension cable. Allow 2 1/2 hours round-trip for the hike up the east side of the river.

Continuing west on Route 47 along the north shore of Hvalfjörður, you'll soon pass a deserted whaling station. At the tip of the peninsula is Akranes, a fishing and cement-factory town of around 6,000. The first settlers, who came as early as 880, are believed to have been Irish hermits. Akranes commemorates its founding each second weekend in July with the Irish Days festival; events include a sandcastle competition, a beach barbecue, and a contest to see who has the reddest hair. Just east of town is Akrafjall, the town's twin-peaked patron mountain. At 555m (1,804 ft.), Akrafjall's southern peak Háihnúkur is a less exhausting climb than Esja. A well-marked trail to the top runs along the edge of a cliff full of great black-backed gulls and other birds. The parking area is along Route 51, at the Akranes hot water utility.

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.