Re manholes: they come in all shapes and sizes (where "all shapes" means "predominantly circular or rectangular"); round manholes are definitely not unique to A

Re manholes: they come in all shapes and sizes (where "all shapes" means "predominantly circular or rectangular"); round manholes are definitely not unique to America. This is mostly an artifact of the construction methods - for prefab cut+cover, rectangular is an easier shape to use; where actual digging is necessary, a round shaft provides a generally acceptable profile.