Five days around the northernmost tip of Vietnam on the hand-cut Happiness Road – karst towers to the horizon, Hmong markets in the folds, and the Ma Pi Leng Pass with the Nho Que a green thread eight hundred metres below.

Sixteen days down the spine of two countries – the Carretera Austral through the cold rainforest, an empty gravel border onto Ruta 40, Fitz Roy, the glaciers, the towers, and at the bottom the sign that says the road has ended.

A week around the High Atlas – over the Tichka to the mud city of Aït Benhaddou, through the Dades and Todra gorges, and home over the Tizi n'Test: single lane, no barriers, built in 1932 and barely apologised for since.

The world's largest war memorial is a road – carved into the cliffs by returned soldiers of the First World War. Out along the surf coast to the Twelve Apostles, then home through the sandstone ranges of Gariwerd.

The province counts the curves on a sign: 1,864. Thailand's highest road, teak forests, a Yunnanese tea village on the Myanmar border, and the 762 bends of Route 1095 saved for the ride home.

In by the old road, out over the top. Up the Suru under Nun and Kun to Rangdum, over Pensi La past the Drang-Drung glacier, three nights at Padum with a day on foot to the cave monastery at Phugtal — then the five-pass trek line turned road: Lingshed, Singge La at 5050 m, Photoksar, and down through the moonland to Lamayuru.

Ladakh past the four-day circuit everyone rides. Eight passes, seven of them above 5300 m, including Umling La at 5798 — then out onto the Changthang for Rezang La, the darkest sky in India at Hanle, and Tso Moriri. Two days at the start doing nothing, which is what makes the rest of it possible.

All three world heritage Chola temples, and the four early ones nobody stops at — Koranganatha on the Kaveri, the circular vimana at Narttamalai, Moovar Koil out in the scrub, and the miniature panels at Pullamangai. Then a Danish fort on the coast, and the Nataraja at Chidambaram on the last morning — two days after watching one cast at Swamimalai.

A clockwise loop out of Bishkek through the Kyrgyz Tian Shan. Issyk-Kul, the red cliffs of Jeti-Ögüz, the 33 switchbacks up to the alpine pastures of Song-Köl, and the Silk Road caravanserai at Tash Rabat. Gravel passes above 3000 m — an adventure-bike ride.

The connoisseur's loop out of Istanbul. Phrygian highlands, Cappadocia, Hattusa the Hittite capital, and the Ottoman timber towns at Safranbolu. Four world heritage sites, and the D010 coastal road ridden both ways.

The greatest hits loop out of Istanbul. Gallipoli, Troy, Pergamon, Ephesus and Pamukkale, then the D400 turquoise coast from Fethiye to Antalya. One rest day, and best avoided in July and August.

One full circle of Turkey in three weeks, and never the same road twice. West first for Troy, Pergamon, Ephesus and Pamukkale, then the Lycian corniche to Antalya. Inland over the Taurus to Cappadocia and the Euphrates canyon at Kemaliye, over the Pontic Alps to Sumela, and home along the Black Sea by the D010. Eleven World Heritage sites.

The second-highest road on earth, Dushanbe to Osh. A gorge with Afghanistan on the far bank, the Wakhan Corridor under the Hindu Kush, then days held above four thousand metres on the plateau. Ak-Baital the high point, Karakul the blue meteorite lake.

The old road across Uzbekistan, west to east. Three great oasis cities — Khiva, Bukhara, Samarkand — with a day of open Kyzylkum desert between the first two. The Registan at dusk, and Timur's tomb before the run up to Tashkent.

The hardest of all of them to arrange. Across the black sand from Kunya-Urgench to Merv, by way of the Darvaza gas crater burning in the dark and the white-marble city of Ashgabat. Three ancient capitals, one modern one.

Up a walled kingdom and back down the only road in. Out of Pokhara, up the deepest gorge on earth between two eight-thousanders, into an ochre desert that used to be Tibet, and Lo Manthang behind its mud walls at the top.

Two Himalayan kingdoms from the Bengal plains, and the floor for doing both. Up the Teesta to Gangtok and the old China border at Nathu La, then across into Bhutan for the dzongs, the 108 chortens of Dochula, and the Tiger's Nest above Paro.

India's far northeast corner, up to a monastery town near Tibet. Rhinos in the Assam grass on the way in, then through Monpa country over Sela pass to Tawang, and a permit run to the old China border at Bum La.

A grand loop of Honshu out of Tokyo. South past Fuji to Ise, Kumano, Nara and Kyoto, then north up the Japan Alps and the volcanic skylines of Tohoku to the lakes of Aomori. Seven world heritage sites, and home by Nikko.

A loop through four countries out of Dubrovnik. The Kotor serpentine and its bay, the length of the Albanian riviera to the Llogara pass, then the Durmitor massif and the Piva canyon before the Neretva home through Mostar.

One line south from Salzburg to Assisi, taking the three great Alpine roads in turn — the Grossglockner, the Timmelsjoch and the Stelvio — then the Gavia, the gorge road at Tremosine, and across the Apennines to Lucca, the Chianti and Umbria.

Down the mezzogiorno and across to Sicily. The cave city of Matera, the trulli and baroque of Puglia, the ferry at Messina, then Etna's lava fields and the golden Val di Noto.

A summer loop of the Romanian Carpathians from Sibiu, on two great passes. South over the Transalpina, the highest road in the country, and back over the Transfăgărăşan's wall of hairpins, with the Saxon towns and Bran castle between.