Ho Chi Minh's preserved home and the museum built beside it draw a steady flow of Vietnamese visitors, which makes Nakhon Phanom one of the few Thai towns where the tour buses arrive from Hanoi rather than Bangkok. The Vietnamese presence here is much older and broader than one famous resident. Families settled across the river through the colonial decades and the wars that followed, and the town's population today is a genuine mix - Thai, Thai-Lao, Thai-Vietnamese, Thai-Chinese - with Isan the language you actually hear in the market. In 1960 the Vietnamese community raised a clock tower on the riverfront as a public thank-you to the town that had taken them in. It still stands on the Mekong walking street, lit in colours at night, with a weekend night market running past its base.

The US airfield west of town, built by Navy Seabees in 1962 and opened for flying the following June, became the home of the 56th Air Commando Wing in April 1967 - redesignated the 56th Special Operations Wing in August 1968. It flew propeller aircraft in a jet age: A-1 Skyraiders, A-26 Invaders, C-123s, AC-119 gunships, and the Nail forward air controllers who found targets on the Ho Chi Minh Trail roughly 48 km east. Rescue squadrons launched from here to pull downed crews out of Laos and North Vietnam. The strangest tenant was Task Force Alpha, which ran the signal-processing centre for Operation Igloo White - air-dropped electronic sensors feeding a room full of machines that tried to read a jungle trail as data. The Son Tay prison raid staged through here in November 1970. The last USAF units left on 1 October 1975.

At the end of Buddhist Lent, communities across the province build scaffolds of bamboo, mount them on boats, and hang them with tin cans of kerosene stuffed with rags. After dark the wicks are lit and the boats are pushed onto the Mekong, and the bamboo frames resolve into blazing outlines - temples, dragons, the king's portrait - drifting downstream past thousands of people standing on the bank. Lai Ruea Fai happens one night a year. The riverfront, which for the other 364 evenings is a place where people walk slowly and eat grilled chicken, becomes the best seat in Thailand.

Thakhek, capital of Laos's Khammouane province, sits directly across the water; from the Nakhon Phanom promenade you are looking at another country's provincial capital over a few hundred metres of current. The Third Thai-Lao Friendship Bridge, opened on 11 November 2011 about 10 km north of town, made the crossing routine - though not on foot, since walking the bridge is not permitted and the international bus runs eight times a day with about ninety minutes of paperwork at each end. Twice a month the border market fills with Lao traders, and among the usual Thai market goods you will find forest produce brought down from the Khammouane karst: roots, wild honey, mushrooms, orchids.

Around town you travel by skylab, the northeast's three-wheeled motorcycle taxi, or you rent a bicycle and take the waterfront cycleway, which runs roughly 12 km north of the city - flat, quiet, scenic and merciless in the afternoon heat. The food argument here is settled: sticky rice, grilled chicken and som tam, at their national best. What Nakhon Phanom does not have is a nightlife, or English menus, or much sense that it needs either. Dinner is a stall on Fuangnakhom Street from four in the afternoon, on a road closed to traffic, with the river going dark beyond it.