A menhir is a large upright staning stone. Menhirs may be found singly as monoliths, or as part of a group of similar stones. Their size can vary considerably; but their shape is generally uneven and squared, often tapering towards the top. Menhirs are widely distributed across Europe, Africa, and Asia, but are most numerous in Western Europe; in particular in the British Isles and Brittany. They originate from many different periods across pre-history, and were erected as part of a larger Megalithic culture that flourished in Europe and beyond.