Berlin lies by the sea. At least, it used to. This was before the Scandinavian glaciers of the last Ice Age pushed across northeastern Germany and left us with a complex geology to explore. Excitingly, these geological processes can still be seen today. Landscape surfaces and sediments store information about the processes that shaped them. Like a coded diary of the Earth, they can provide information about the multiple changes from land to sea. Take, for example, the Brandenburg Zechstein Sea, which reached as far as Berlin. It was formed around 260 million years ago by flooding what is now the North Sea and lasted for a very short time. It evaporated almost completely several times, leaving behind salt rocks that tell us of its existence today.

On this eight-stage, 899-kilometre (552 mi) bikepacking tour, you cycle once to the sea and back. Depending on the wind direction, you can ride it counterclockwise, as suggested here, or in the other direction. The trails are all suitable for a touring bike, but can also be ridden well on a road bike with slightly wider tyres if you don't mind sections on forest and gravel paths. In the Brandenburg villages, you occasionally ride over cobblestones. Each stage ends at a bivouac site or near a campsite.

Mainly on cycle paths and quiet country roads, the tour takes you through a varied sequence of different landscapes shaped by the Ice Age. From the Barnimer Feldmark, it goes through the Lower Oder Valley National Park along the German-Polish border towards the Baltic Sea. Past the Szczecin Lagoon, through the moorlands of the Anklamer Stadtbruch and the Peenetalmoors, you finally reach the island of Usedom with its enchanted dune forests.

The tour now runs parallel to the coast past the island of Rügen to the Vorpommersche Boddenlandschaft National Park, from where you can see Denmark on a clear day. The sea, the wide sandy beaches with their grassy dunes and the salty wind invite you to take a break here for a day.

The Rostock Heath, a huge coastal forest, will be your last maritime section before you reach the Mecklenburg Lake District and the Müritz National Park. This lake landscape, nestled in untouched forests and grassland, offers countless swimming opportunities.

The last major section starts at Müritz. You pass the Rüthnicker Heide and the Spandauer Forst forest on your way back to Berlin. Alternatively, you can cycle back along the Berlin-Copenhagen Cycle Path through the small Schorfheide. Take a look at the first stage of my Uckermark Bikepacking Collection: komoot.com/collection/1882593. You would then cycle this stage in the opposite direction from Bredereiche.