Scale more than 1,000 steps to reach a secret passageway slicing through the summit of the Phu Kheng Jar Quarry Site that played a strategic role for Pathet Lao forces during the Indochina war (1964-1973). The hardy climb passes an odd mix of bomb craters and unfinished or broken jars destined for Jar Site 1. The steps get steeper, but the reward is a magnificent view of the valley around Phonsavanh and the hidden entrance to a narrow 70-metre-long, 1.6-metre-high tunnel chiselled through rock that winds past re- inforced concrete bunkers and sleeping quarters before exiting to a panorama of the Phoukoud Valley.
Location: From Phonsavanh, follow Route 7 west past the Mulberry Farm and across a river. Turn left after 8 km at the “Phu Kheng Jar Quarry Site” sign and continue 7 km to the visitor centre.