Acheulean stone tools have been found across the continent of Africa, save for the dense rainforest around the River Congo which is not thought to have been colonized by hominids until later. It is thought that from Africa their use spread north and east to Asia: from Anatolia, through the Arabian Peninsula, across modern day Iran and Pakistan, and into India, and beyond. In Europe their users reached the Pannonian Basin and the western Mediterranean regions, modern day France, the Low Countries, western Germany, and southern and central Britain. Areas further north did not see human occupation until much later, due to glaciation. In Athirampakkam at Chennai in Tamil Nadu the Acheulean age started at 1.51 mya and it is also prior than North India and Europe.