The banana pancake trail

In the late 1960s and 1970s the overland hippie trail ran from Europe through Istanbul, Tehran and Kabul to Kathmandu and Goa. Some travellers carried on east to Bangkok, Penang and Bali, but most of mainland Southeast Asia was closed: war in Vietnam, Laos and Cambodia shut all three to casual visitors after 1975. The Asian leg of the circuit shrank to Thailand, Malaysia and Indonesia.

Guidebooks shaped the route as much as the maps did. Tony and Maureen Wheeler founded Lonely Planet after their own overland trip in 1972–73, and their South-East Asia on a Shoestring, first published in 1975, became known among travellers as the yellow bible. Its recommended guesthouses turned into hubs. In Bangkok the narrow Khao San Road, near the old royal quarter, filled with cheap rooms, travel agents and cafés from the early 1980s.

The loop opened country by country. Vietnam's Đổi Mới reforms of 1986 led to tourist visas in the late 1980s and a rush of backpackers in the 1990s. Laos began admitting independent travellers around the same time. Cambodia became reachable after the 1991 Paris peace agreements and the UN-run elections of 1993, although the Khmer Rouge held out in the north-west until 1998 and roads to Angkor stayed rough for years.

The name came from the menus. Guesthouse owners along the route found that Western travellers ordered banana pancakes, fruit shakes and toast, and those dishes spread from Khao San Road to Vang Vieng and Hội An. By the 2000s the phrase banana pancake trail was used, half fondly and half mockingly, for the whole circuit and for travellers who stayed inside its bubble. Alex Garland's 1996 novel The Beach, and the 2000 film made from it, captured the same world and its disillusion.

The trail has changed. Low-cost airlines, e-visas and ride-hailing apps have made it quicker and less adventurous; the Laos–China railway cut a day of mountain road to an hour. The guesthouse strips are still there, but the travellers now include retirees, families and digital nomads, and domestic tourists from Vietnam, Thailand and China far outnumber backpackers at most stops.

For about six centuries, Angkor was the centre of the largest state in mainland Southeast Asia. Tradition dates the empire to 802, when Jayavarman II had himself declared a universal monarch on the Phnom Kulen plateau north of Siem Reap. At its height the Khmer kings ruled or took tribute from much of today's Thailand, Laos and southern Vietnam; Khmer-style towers still stand in north-east Thailand and in Vientiane's museums.

Angkor Wat was built in the first half of the 12th century under Suryavarman II as a temple to Vishnu and, most scholars think, his own funerary monument. It faces west, the direction associated with death, and its 800 m of bas-relief galleries show Hindu epics and the king's army. Its five towers represent Mount Meru, the centre of the Hindu-Buddhist universe, surrounded by a moat that stands for the cosmic ocean.

A generation later Jayavarman VII, who ruled from 1181 to about 1218, turned the empire towards Mahayana Buddhism after driving out a Cham invasion. He built the walled city of Angkor Thom with the Bayon at its centre, whose towers carry more than two hundred huge smiling faces, and the monastic temples of Ta Prohm and Preah Khan, as well as roads, rest houses and hospitals across the empire.

The city depended on water. Huge rectangular reservoirs called baray, the West Baray is 8 km long, and a web of canals stored monsoon water and moved it across the plain. Aerial laser surveys since 2012 have shown a low-density urban area far larger than the stone temples, home to perhaps several hundred thousand people. Its decline in the 14th and 15th centuries is now linked to failing waterworks, drought and floods as much as to war.

Ayutthaya's armies took Angkor around 1431, the traditional date for the end of the empire, and the Khmer court moved south towards Phnom Penh. Angkor Wat was never fully abandoned; it became a Theravada Buddhist monastery. French naturalist Henri Mouhot's published account of his 1860 visit made it famous in Europe, and French archaeologists cleared and restored the site during colonial rule. It became a UNESCO World Heritage Site in 1992 and appears on Cambodia's flag.

Every country on this loop was a battlefield between 1945 and 1979, and the sites that explain it are among the most visited on the trail. The war known in Vietnam as the American War spread across all three Indochinese states, and its consequences — a Khmer Rouge regime in Cambodia, unexploded bombs in Laos — outlasted the fighting by decades.

Laos is, per person, the most heavily bombed country in history. Between 1964 and 1973 the United States flew more than 580,000 bombing missions over Laos, aimed at the Ho Chi Minh Trail supply lines and at communist forces on the Plain of Jars. Around 270 million cluster submunitions were dropped, and an estimated 80 million failed to explode. They still kill and injure farmers and children every year. The Plain of Jars in Xieng Khouang, a field of ancient stone jars listed by UNESCO in 2019, can only be visited on cleared paths.

In Vietnam the war left museums on both sides of the line. In Ho Chi Minh City the War Remnants Museum shows the effects of bombing and Agent Orange; at Củ Chi, north-west of the city, a network of some 200 km of tunnels hid Việt Cộng fighters close to a US base. In Hanoi the Hỏa Lò prison, built by the French for Vietnamese prisoners and later called the Hanoi Hilton by the American pilots held there, now presents both histories. Quảng Trị province near Huế, along the old demilitarised zone, remains the most contaminated with unexploded ordnance.

Cambodia's worst years followed the war. The Khmer Rouge took Phnom Penh on 17 April 1975, emptied the cities and declared Year Zero. In under four years, through execution, starvation and forced labour, about 1.5 to 2 million people died, close to a quarter of the population. Tuol Sleng, a Phnom Penh school turned into Security Prison 21, held more than 14,000 people, of whom only a handful survived; most were killed at Choeung Ek outside the city. Vietnamese troops invaded in December 1978 and took Phnom Penh on 7 January 1979.

Justice came late. A UN-backed tribunal convicted the head of S-21, known as Duch, in 2010, and the senior leaders Nuon Chea and Khieu Samphan of genocide in 2018; Pol Pot died in 1998 without trial. Visitors are welcome at all these sites, but they are memorials. Speak quietly, dress modestly, avoid posed photographs, and take the audio guides, which are recorded with survivors' testimony.

The Mekong rises on the Tibetan plateau and runs roughly 4,500 km through China, Myanmar, Laos, Thailand, Cambodia and Vietnam to the South China Sea. This route meets it five times: at Luang Prabang, at Vientiane on the Thai border, at Phnom Penh, in the Delta south of Ho Chi Minh City, and, for many, on the two-day slow boat from the Thai border to Luang Prabang.

Luang Prabang grew on a peninsula where the Nam Khan joins the Mekong, a site of royal power from the 14th-century kingdom of Lan Xang, the land of a million elephants. Vientiane, downstream, became Lan Xang's capital in the 1560s. For most of history the river connected Lao and Thai towns rather than dividing them; people on both banks speak closely related languages and share festivals.

In Cambodia the river does something unusual. During the rainy season, from about June to October, the Mekong rises so high at Phnom Penh that it pushes water backwards up the Tonle Sap river into the great lake, which swells to several times its dry-season area and floods the forest around it. In November the flow reverses, and Cambodians celebrate with the Bon Om Touk water festival and boat races. The lake's fishery feeds much of the country; stilt villages near Siem Reap rise and fall with it.

The Vietnamese call the Delta Cửu Long, nine dragons, for the branches through which the river reaches the sea. It is Vietnam's rice bowl, a flat maze of canals, floating markets and orchards. It is also sinking and turning salty: dams upstream trap sediment, sand mining deepens channels, and sea water now pushes further inland in the dry season.

Dams are the river's big question. China has built a chain of large dams on the upper Mekong since the 1990s, and Laos, which hopes to sell electricity to its neighbours, has built others, including the Xayaburi dam on the main stream, operating since 2019. Fishers downstream report falling catches, and droughts in 2019–2020 exposed sandbanks never seen before. On the slow boat and at Phnom Penh you are looking at a river whose future is being argued over in six capitals.

Most borders on this loop were drawn by France. It took Cochinchina (southern Vietnam) in the 1860s, made Cambodia a protectorate in 1863, added Annam and Tonkin in the 1880s and formed French Indochina in 1887. Laos was added after the Franco-Siamese crisis of 1893, when French gunboats forced Siam to give up the land east of the Mekong. That is why the river is the Thai–Lao border for long stretches.

Siam lost more ground in treaties of 1904 and 1907, which handed the provinces of Battambang and Siem Reap back to Cambodia, so Angkor passed from Siamese to French control. Thailand retook them during the Second World War with Japanese backing and returned them in 1946. The temple of Preah Vihear on the Thai–Cambodian border remains disputed; the International Court of Justice awarded it to Cambodia in 1962 and clarified the ruling in 2013.

After 1975 the borders hardened into front lines. Thailand's border with Cambodia became a string of refugee camps, and the Lao and Cambodian crossings were effectively closed to foreigners. The land crossings travellers use now opened in stages from the late 1980s and 1990s. The Thai–Lao Friendship Bridge across the Mekong opened in 1994; Poipet and Bavet grew into casino towns because gambling is illegal for locals in Thailand and Vietnam.

E-visas changed the trail more than any road. Cambodia launched one in 2006, Vietnam piloted its e-visa in 2017 and in August 2023 opened it to all nationalities for up to 90 days, and Laos introduced its own in 2019. Each is sold only on a government portal, yet dozens of lookalike sites charge extra; the official addresses are in this route's sources. Not every land border accepts every e-visa, so always check the list of ports.

Railways are now stitching the borders together. The Laos–China Railway opened on 3 December 2021, linking Vientiane, Vang Vieng and Luang Prabang with Kunming; cross-border passenger trains to China started in 2023. A short line crosses the Friendship Bridge to Nong Khai in Thailand, extended to Vientiane's Khamsavath station in 2024, and through trains to Bangkok followed (check current services). Plans to link Bangkok to Phnom Penh and Ho Chi Minh City by rail exist, but for now the rest of the loop moves by bus, boat and plane.