Grotte de Spy, Paleolithic cave in Jemeppe-sur-Sambre, Belgium.

Grotte de Spy opens in a rock face about 20 metres high above the left bank of the Orneau. Its main porch, 4 to 5 metres high and 6 to 11 metres deep, is split by a massive pillar with open chimneys; a smaller arcade opens to the left at mid-height. The cave consists of numerous small chambers and corridors.

The cave was studied in 1886 when explorers uncovered two Neanderthal skeletons that provided crucial insight into early humans. These discoveries fundamentally changed how scientists understood human development and made the location a landmark in paleontology.

In Walloon the cave is called Bètch aus Rotches, "the beak of the rocks", after the hole forming its entrance, said to resemble a hooked eagle's beak. Excavators long doubted that the Neanderthal dead were deliberately buried, a reading now widely accepted. Pendants and perforated beads of mammoth ivory, presumably made by modern humans, were found in the cave.

The cave lies on a wooded slope on the left bank of the Orneau, south of Onoz in Jemeppe-sur-Sambre. It is on private property, and access is allowed via the plateau of the Spy communal wood or the footpath along the Orneau. Climbing is forbidden.

The cave sediment holds over 12,000 animal bones from the Pleistocene, including mammoth remains, showing that humans and large creatures coexisted for a long time. This collection offers rare clues about the environment and hunting practices of that era.