Deepest marathon
- Who
- Untertage Sparkassen Marathon
- Where
- Germany (Sondershausen,)
- When
- 2002
The deepest marathon is the Crystal Mine Undeground Marathon (Untertage Sparkassen Marathon) run in an old salt mine located 500 m (1,640 ft 5 in) below sea level in Sondershausen, Thuringia, Germany, annually since 2002.
The course record is 3 hrs 1 min 21 secs by Michael Muller (Germany) on 17 November 2012.