Embankment Culvert

Built stone headwall marking where a brook or a farm track passes under the railway embankment: a coursed-stone face wall 0.6 m thick with a round arch, a projecting keystone, a string course and a dead level coping the bank's top meets.

风格：low-poly, flat-shaded vertex colors, no textures, single shared material, so any set of these merges to one draw call; shares palette and scale with its kit