The Swartendijk stretch lies on the quiet side of the hills, away from the villas and museums of Berg en Dal. This is where the Heilig Land Stichting, the Holy Land Foundation, was set up in the nineteenth century by Dutch Catholics, who built an enormous religious theme park with replicas of biblical sites, a Golgotha, a Jordan river and a Holy Sepulchre, in the woods and hills near the German border. It still exists, though it now has the air of a very large and slightly surreal garden, and it stands as a reminder that these slopes have been a place of pilgrimage as well as war.
The Roman aqueduct belongs to this landscape too. The springs on the hillside near here fed the water channel that ran to Nijmegen's fortress, and the line of the water supply is a part of the Lower German Limes UNESCO listing. The Duivelsberg, the devil's hill, rises near the border and is one of the highest points in the area, with a legend of the devil living in it. The hills are the sandy leftovers of an Ice Age glacier and the woods are mostly beech and oak.
Riding here is pleasant in a modest way. Narrow roads wind through the forest, with sunken lanes and short climbs that count as serious hills in the Netherlands, and crossing into Germany at Beek takes you to the Reichswald with its long straight forest roads. Road surfaces are generally good, though autumn leaves can be slippery and farm tractors are common. Keep to the speed limits, as police here are diligent.
For fuel, go back toward Nijmegen or to Groesbeek, because the hill villages do not offer much. Cafes and small restaurants offer pancakes and local beer, and the Dutch concept of gezelligheid, a kind of warm cosiness, is at its best on a damp afternoon in a wood-panelled cafe.
Spring is the best time, when the beech leaves emerge a luminous green, followed by golden October. Summer weekends can bring crowds, especially on the cycling routes. In winter the fog sits in the hollows, and the whole area becomes still and grey. Leave the bike at the foot of a lane and walk a while, because the slopes deserve it.