Across Western Europe, the Early Neolithic marked the first period in which humans built monumental structures in the landscape. These were tombs that held the physical remains of the dead, and though sometimes constructed out of timber, many were built using large stones, now known as "megaliths". Individuals were rarely buried alone in the Early Neolithic, instead being interned in collective burials with other members of their community. The construction of these collective burial monumental tombs, both wooden and megalithic, began in continental Europe before being adopted in Britain in the first half of the fourth millennium BCE.