It took three borders to get in. Then it took a month to cross.

Arriving at sunset, and sleeping in a park.

I came into Istanbul at rush hour with the sun going down over the Bosphorus, and by my own account nearly rode into a truck because I could not stop looking at it. Years of imagining the moment of leaving Europe behind, and it happened in traffic.

That night I had nowhere to stay. I parked beside a KTM outside a hotel near the Hagia Sophia and got talking to the man out front, who turned out to own the restaurant upstairs, who had cooked in Spain for years, who took an immediate liking to Jacko, and who ended up leading me on my own motorcycle to a quiet park where I could camp. The hotel became my base for the rest of the week.

I had him wrong at first. Long black hair, big sideburns, dressed anyhow, standing outside calling people in off the street: I took him for someone working the pavement for tips. He turned out to be the chef, and the owner. He kept phoning around hotels trying to find one that would take the dog, and could not be talked out of it.

I pitched between some railings in a corner of the park where nobody would come near, with families still eating under the trees. In the morning the only person about was the guard, and I passed him a few coins through the fence and asked him to buy me a coffee from the shop on the other side.

At dawn the next morning I rode over the Bosphorus bridge with the camera running. Jacko and I were officially in Asia.

For the first time in my life, the sun came up in Asia.

I had spent years imagining the moment of leaving Europe behind. The Bosphorus is the line: about seven hundred metres of water separating the two continents, with fifteen million people living on both sides of it.

Down the Aegean, and a family in Fethiye.

South through Çanakkale and the Dardanelles, past Pergamon and Ephesus, then along a coastline that goes from Greek ruins to turquoise water without much warning.

In Fethiye a young woman called Maria and her family took me out on their catamaran for a day, swam at three different bays, fed me, and refused to charge me anything. I spent the evening on the waterfront with Maria and her partner Orhan, who rides two GS's and marked up the rest of the country for me. That evening is the reason the route east looks the way it does.

The same day a towel worked its way into the chain and nearly ended the trip. That is also how it goes.

The towel was wrapped around the chain like an anaconda squeezing with everything it had.

A caravanserai, a salt lake and a hundred balloons.

Inland over the Taurus mountains to Konya, and then Sultanhanı, reached at eleven at night: a fortified thirteenth century inn built for Silk Road caravans, still standing, with women weaving carpets in the arcades.

North of it, Lake Tuz dries out in summer into a salt crust you can ride onto. East of it, Cappadocia, where the rock is soft enough to carve houses into and about a hundred balloons go up together at first light.

Along the Syrian border to Mesopotamia.

The road east runs close to Syria for hundreds of kilometres. At Öncüpınar I stood at the crossing and asked people whether I should go over. The answers split evenly between an emphatic no and yes, but be careful. I did not cross.

Instead: the Zeugma mosaics at Gaziantep, a boat on the Euphrates at Halfeti over a village that is now underwater, the colossal heads on Mount Nemrut at 2,134 metres, and Mardin, looking out over the Mesopotamian plain from a hillside of honey coloured stone.

At Silopi I crossed into Iraq. I came back through the same gate a week later.

Mount Nemrut is the tomb of Antiochus I of Commagene, built in the first century BC with colossal statues of the king and his gods facing east and west. Earthquakes brought the heads down and they were never put back. It has been a UNESCO World Heritage Site since 1987.

Mountains, sheep, and a lake at the far corner.

Hakkâri is the emptiest part of the country: the road follows the Zab river through gorges for hours and the only traffic is livestock. Then Van and its lake, İshak Pasha Palace on its ridge at Doğubayazıt with Ararat behind it, and a salt mine at Tuzluca with pink walls.

The last night was on Lake Çıldır at nearly two thousand metres, close enough to Armenia to see it. I arrived picking litter off the shore, assuming it belonged to the couple already camped there. They were doing the same thing. Nobody spoke a word of the other's language and they got on fine.