
1) Challenge walk
Found on
https://www.crosswordclues.com/clue/dodentocht

The Dodentocht (Dutch for March of the Dead) is a long-distance march of 100 kilometers organized annually in Bornem, Belgium, since 1970. The grueling march derives its name from the length of the march and the rough and forested terrain. For the 2014 edition, 11,861 participants have registered; a scouting group also organises a campsite for the...
Found on
http://en.wikipedia.org/wiki/Dodentocht
No exact match found.