The land that became Champasak province was already ancient when Lao people arrived. In the first centuries of the common era, the area belonged to the realm of Chenla, and one of its capitals — Shrestapura — was located here, presumably near the site of what is now Vat Phou. From the tenth through thirteenth centuries, the Khmer Empire incorporated the region, building stone temples and the elaborate water management infrastructure characteristic of Angkorian civilization.

When the Khmer Empire contracted, the population that remained spoke languages distantly related to Khmer — the Kuy people, who had settled the region after the empire's peak. Lao-speaking people arrived only around 1700, migrants from Vientiane who had dispersed after the disintegration of the Lan Xang Empire. The new polity they built was led first by a popular monk, then by a daughter of Lao king Sulinyavongsa. An entire civilization's worth of history already lay beneath their feet, carved in sandstone on the slopes of Phou Khao mountain.

UNESCO designated the Champasak Cultural Landscape as a World Heritage Site, centering the designation on Vat Phou and its associated ancient settlements. This is not a single monument but a layered geographic relationship: the mountain whose summit resembles a Shiva lingam, the spring that emerges from its base, the causeways and reservoirs that structure the approach to the temple, and the flat Mekong floodplain that frames it all from the east.

Vat Phou itself sits 43 kilometers south of Pakse, accessible via the small town of Champasak on the Mekong's west bank. The ruins of Um Muang, 44 kilometers south of Pakse, were built around the same period as Vat Phou and feature two Khmer sanctuaries with sandstone nagas and lingas, though that site remains uncleared jungle, far less visited, and correspondingly more atmospheric for those willing to reach it by boat and trail.

Prince Boun Oum of Champasak is the province's most consequential modern figure, and his story illuminates the turbulent path from French colony to independent nation. In 1945, he formally relinquished his family's centuries-old right to rule the Kingdom of Champasak in favor of the unified Kingdom of Laos — a gesture of national solidarity at a moment of flux. Thirteen years later, when the Lao civil war began in 1959, he had become the head of the rightist faction, the conservative forces aligned with the United States against the Pathet Lao communist movement. His stronghold was here, in the province his family had ruled.

The civil war ended badly for his side. After the communist victory in 1975, the royal and rightist order that Boun Oum represented was swept away. He died in Paris in 1980. Today the former royal palace in Pakse — converted into a hotel — is one of the more distinctive places to sleep in the city, its imperial ambitions reduced to a curiosity for passing travelers.

For all its historical weight, Champasak province today is a place of rice paddies, fishing villages, and island life. With 45 inhabitants per square kilometer, it is one of the more densely populated parts of Laos — though that statement requires the context that Laos as a whole is one of Southeast Asia's most sparsely peopled countries. The province's human development index runs slightly above the Lao average, and considerably higher than neighboring Salavan and Attapeu.

The Mekong defines the province's geography and daily life in equal measure. To the south it spreads into Si Phan Don — the Four Thousand Islands — where the river fragments into channels and braids around low islands, some inhabited, some not. The border with Cambodia is marked not by a wall or a fence but by the Khone waterfalls, where the Mekong makes its great drop before continuing south. Champasak is a province that rewards exploration at low speed, on motorbike or by river, stopping where the road bends toward something old.