Belgrade is a city built on a fault line between worlds, and it announces the fact where the Sava river meets the Danube beneath the old fortress of Kalemegdan. This is where the ride begins, in a capital of well over a million people, noisy, restless, a bit scruffy and constantly alive. It has been fought over by Romans, Byzantines, Hungarians, Ottomans and Austrians, and the fortress walls carry the scars of all of them. Climb up in the early morning, before the day starts, and you can look across the confluence to the flat green plains of Vojvodina.
Getting out is the only part that needs patience. Belgrade traffic is dense, drivers are assertive, tram tracks and cobbles lie in wait, and the ring roads can be slow at rush hour. Once past Zemun, an old Habsburg town on the Danube that still has its own Austro-Hungarian feel, things loosen up and the river road begins. Fuel is on every other corner, so top up before you leave the city and carry some cash for tolls and small shops along the way.
The Danube route east is a real journey. You pass the huge fortress of Smederevo, built in the 1400s by the Serbian despot Đurađ Branković as the last redoubt before the Ottomans overran the country. Then the landscape tightens as the river is squeezed through the Iron Gates, a gorge on the border with Romania, with cliffs on both banks and fortresses like Golubac standing on the shore. Farther on, a carved Roman inscription commemorates the legions who first built a road along this wall of rock.
Before you ride out, eat. The Belgrade bakery breakfast of burek, a flaky cheese or meat pie, with yoghurt, is a local ritual, and later in the day a kafana, the traditional tavern, will serve grilled meat with kajmak, a salty cream spread, and a rakija, the local fruit brandy, that you should treat with respect before getting back on the bike. The spring and autumn light on the water is the best of the year, and the summers are hot and humid, so the early start makes sense.