Continue driving northwest until you reach the twin communities of Allinge and Sandvig. Allinge, whose architecture is noticeably older than that of Sandvig, contains 200- and 300-year-old half-timbered houses built for the purveyors of the long-ago herring trade, and antique smokehouses for preserving herring for later consumption or for export abroad.
The newer town of Sandvig, a short drive to the northwest, flourished around 1900, when many ferryboats arrived from Sweden. Sandvig became a stylish beach resort, accommodating guests at the Strandhotellet.
The forest that surrounds these twin communities is known as the Trolleskoe (Forest of Trolls), home to wart-covered and phenomenally ugly magical creatures that delight in brewing trouble, mischief, and the endless fog that sweeps over this end of the island.
From Allinge, detour inland (southward) for about 4km (2 1/2 miles) to reach Olsker, site of the Olskirke (Round Church of Ols), Lindesgordsvej (tel. 56-48-05-29). Built in the 1100s with a conical roof and thick walls, it's the smallest of the island's round churches. It was painstakingly restored in the early 1950s. Dedicated to Skt. Olav (Olav the Holy, king of Norway, who died in 1031), it looks something like a fortress, an image that the original architects wanted very much to convey. June to September, and October 17 to 18, it's open Monday to Saturday 2 to 5pm; April and May, and October 1 to 16, it's open Monday to Friday 10am to 1pm. It's closed the rest of the year. Entrance costs DKK10 ($1.70/£1).
Now retrace your route back to Allinge and head northward toward Sandvig, a distance of less than a kilometer (1/2 mile). You'll soon see Madsebakke, a well-signposted open-air site containing the largest collection of Bronze Age rock carvings in Denmark. Don't expect a building, any type of enclosed area, or even a curator. Simply follow the signs posted beside the main highway. The carvings include 11 depictions of high-prowed sailing ships of unknown origin, and were made in a smooth, glacier-scoured piece of bedrock close to the side of the road.
From here, proceed just less than a kilometer (1/2 mile) to the island's northernmost tip, Hammeren, for views that -- depending on the weather -- could extend all the way to Sweden. Here you'll see the island's oldest lighthouse, Hammerfyr, built in 1871.