Forty-seven million years ago, in a warm, subtropical world, a deep volcanic lake lay where the forest near Messel now stands, a few kilometres northeast of Darmstadt. The lake's depths were starved of oxygen, and animals that fell or sank into it were preserved in fine layers of mud with extraordinary detail: not just skeletons, but skin, feathers, fur, the contents of stomachs and even the colours of beetles' wings. Over time the mud turned into oil shale, which was mined here from the nineteenth century until 1971. After mining ended, there were plans to turn the pit into a rubbish dump; scientists and local people fought the plan, and in 1995 the pit became Germany's first natural World Heritage site.
The finds are astonishing. There are early horses no bigger than a fox, with their last meals of leaves and grapes preserved; bats with their wing membranes intact; birds, crocodiles, turtles, insects and the primate known as Darwinius masonae, nicknamed Ida, unveiled in 2009 with great fanfare as a possible ancestor of humans, a claim most scientists later dismissed. Every year, excavations bring up new species. A visitor centre explains the science, and guided tours take visitors down into the pit itself, a deep, scarred hole surrounded by forest, where you can see the dark layers of shale.
The landscape around Messel is wooded and gently rolling, at the northern edge of the Odenwald and the southern edge of the Rhine-Main area, so it is a mix of forest, villages, suburbs and roads. The riding nearby is pleasant but not spectacular; the real riding starts in the Odenwald to the south, where roads like the Nibelungenstraße wind through hills, forests and villages, with many curves and popular biker cafes. Weekend traffic around Frankfurt and Darmstadt is heavy, and speed cameras are common.
Messel itself is a small village with basic shops; Roßdorf, about six kilometres away, and Dieburg have fuel and more services, and Darmstadt, with its Art Nouveau artists' colony on the Mathildenhöhe, also a World Heritage site, has everything. Try Handkäse mit Musik, a tangy sour-milk cheese with onions and vinegar, and a glass of Ebbelwoi, the local cider, in a traditional tavern.