The Plain of Jars is one of Southeast Asia's great riddles: across the Xieng Khouang plateau in northern Laos, thousands of huge stone jars lie scattered over hillsides, in groups of a few or a few hundred, some taller than a person. They were carved from sandstone and other rock during the Iron Age, roughly between 500 BC and AD 500, and the most widely accepted theory is that they were linked to funerary practices, perhaps used to let bodies decompose before final burial. Local legend has a happier explanation: the jars were made to brew rice wine for a victory celebration of a mythical king. The sites were added to the World Heritage list in 2019, and Site 21 is one of the many numbered groups in the countryside around Phonsavan.
The beauty of the outer sites is that you often have them to yourself, with only buffalo grazing among the jars and pine trees whispering in the wind. The plateau lies at over a thousand metres, which makes it cooler than the lowlands, with rolling grassy hills and pine forest that feel unlike anywhere else in Laos. The mornings can be foggy and cold in the dry season, from November to February.
The plateau also has a terrible recent history. During the secret war of the 1960s and early 1970s, the United States dropped enormous quantities of bombs on Laos, and Xieng Khouang was among the most heavily hit areas. Bomb craters still pockmark the land around the jars, and unexploded ordnance remains a daily danger. At the visited sites, the paths have been cleared by mine clearance teams and are marked with small posts; stay strictly between the markers. Phonsavan has visitor centres that explain the clearance work, and they are worth a visit.
Route 7, the main road across northern Laos, passes through Phonsavan and is a great ride, climbing and twisting through mountains and villages, although the surface can be broken and trucks are frequent. The tracks to the outer jar sites are often dirt, dusty in the dry season and muddy in the rainy season. Phonsavan, about eleven kilometres away, is the only real town in the area, with fuel, guesthouses and restaurants, so fill up there and bring water and snacks.