Despite a long history of research in mainland Southeast Asia, Pleistocene human remains are rare and fragmentary. After spending 20 years excavating and surveying in the region, our team could identify two key sites for human palaeoanthropology in Northern Laos: Tam Pà Ling and Tam Ngu Hao 2 caves. Both caves are part of the Annamite Mountains, which lie east of the Mekong River and extend through Laos, Vietnam, and into northeastern Cambodia. This is a limestone karst landscape featuring an extensive network of sinkholes, towers, and caves. Tam Pà Ling, or the Cave of the Monkeys, is located at an altitude of 1170 m and is an accumulation site where sediments have been washed into the cave to form regular horizontal deposits. Hominins never occupied the cave, yet remains of seven modern humans dated to 78-30 Ka have been recovered, documenting an ancient presence of our species in the region. Tam Ngu Hao 2, or Cobra Cave, is located at an altitude of 1116 m and dated to 164-131 ka. This is also an accumulation site where the sediments are found on the walls of the cave in the form of breccia. This fossiliferous breccia yielded a hominin lower molar that is attributed to a young female Denisovan by both palaeoproteomics and geometric morphometrics analyses. This recently published discovery of a Denisovan in the tropics broadly expands the territory of this hominin, which was previously thought to be limited to cold regions. A fresh look at the fossil record from the surrounding regions could potentially identify additional candidates for attribution to the Denisovans that were traditionally undesignated or assigned to an undefined group.