low-poly medieval castle 3d model

Low-poly medieval stone castle, fully solid watertight mesh, optimized for 3D printing (STL), no hollow interiors, no thin walls, thick structural geometry, simplified shapes, clean topology, manifold geometry, no holes, no floating parts, connected mesh. Features: square keep, four corner towers, crenellated walls, simple gatehouse, minimal details, chunky proportions. Style: low poly, stylized but realistic proportions, flat shading, no textures, no materials, no colors. Geometry requirements: closed volume, uniform wall thickness, no internal cavities, no intersecting meshes, no overhangs beyond 45 degrees, stable base. Output: single unified mesh, printable, repair-free STL.