Acheulean bifacial tools (hand-axes) from Burnham Beeches, Bucks. Upper Boyn Hill Terrace. Acheulean is an archaeological industry of stone tool manufacture characterized by distinctive oval and pear-shaped "hand-axes" associated with early humans. Acheulean tools were produced during the Lower Paleolithic era. The Lower Paleolithic is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 2.5 million years ago when the first evidence of craft and use of stone tools by hominids appears in the current archaeological record, until around 300,000 years ago.