| Alt-Trauchburg | |
|---|---|
Alttrauchburg, Trauchburg | |
| Weitnau-Alttrauchburg | |
 The southwest side of the inner bailey | |
  Alt-Trauchburg  Alt-Trauchburg | |
| Coordinates | 47°39′18″N 10°06′33″E / 47.6551°N 10.1092°E |
| Type | hill castle, spur castle |
| Code | DE-BY |
| Height | 903 m above sea level (NN) |
| Site information | |
| Condition | considerable wall remains |
| Site history | |
| Built | 1100 to 1200 |
| Materials | conglomerate ashlar |
| Garrison information | |
| Occupants | nobility |
The ruins of Alt-Trauchburg Castle (German: Burg Alt-Trauchburg), also called the Alttrauchburg or Trauchburg, lie above the Weitnau hamlet of Kleinweiler in the county of Oberallgäu in Swabia. Large parts of the original stone walls of the high- to post-medieval castle remain. The ruins are some of the best preserved in the Allgäu region of Germany.