Ubon Ratchathani

Fly (about an hour from Bangkok, several airlines daily, usually the cheapest Isan route) or take the overnight sleeper train, which terminates here after 8–10 hours. The station is actually in Warin Chamrap across the Mun River, ten minutes from the center. Buses take 8–9 hours. Ubon also works as the endpoint of a rail loop through Korat, Buriram, and Surin.

Around Asahna Bucha and Khao Phansa, the July full moon, with the grand procession on the main morning and the carved candles displayed around Thung Si Mueang field for days on either side. Dates shift with the lunar calendar, so check the current year. Book rooms well ahead. It's the one week Ubon's hotels genuinely fill.

Yes, and it's the best half-day in the province. The 75 km drive east passes Wat Sirindhorn Wariram (come back through at dusk for the glow murals), and Khong Chiam itself offers the two-color river confluence, riverside fish restaurants, and Thailand's first sunrise from Pha Taem country. Without your own wheels, I'd hire a driver for the loop (~฿1,500). Public transport out there is thin.

Two sits right: one for the city's temples and the Mun riverfront night market, one for the Mekong loop east to Khong Chiam. Festival week deserves an extra day for the processions. Ambitious travelers add Pha Taem's cliff paintings and Sam Phan Bok's rock canyon (dry season only), but those push past the day-trip radius and reward an overnight in Khong Chiam.