Sketchfab really is impressive! First are castles (since that was requested)
- https://sketchfab.com/models/9097d857a07b4c2daa5d2831ff824aa7
- https://sketchfab.com/models/f72c7df08e674d17b2e1299b2480a8a8
- https://sketchfab.com/models/694b59ee9b654fd69e8572891ad5a1af
- https://sketchfab.com/models/99711b9661c74f2aa2ca6d4d535a9efe
- Model downloads https://sketchfab.com/download
- https://sketchfab.com/models?features=downloadable
- e.g. https://sketchfab.com/models/categories/architecture?features=downloadable
- https://sketchfab.com/models/88fbd157729b44fdb44637f715d88d77
- Brazil country house e.g. Archaeology https://sketchfab.com/models/categories/3d-scans/archeology?features=downloadable