Gallery grave

A gallery grave is a form of megalithic tomb built primarily during the Neolithic Age in Europe in which the main gallery of the tomb is entered without first passing through an antechamber or hallway. There are at least four major types of gallery grave (complex, transepted, segmented, and wedge-shaped), and they may be covered with an earthen mound (or "tumulus") or rock mound (or "cairn").