I you will like this one.
http://www.geocaching.com/seek/cache_details.aspx?guid=0c3992bb-de3a-4a40-bd82-9259b2fd3cc1
Nice walk in pure nature. May be a bit longer than 8 km, but i had my 9 year old niece with me.
This is a multi, but each waypoint is a traditional on his own.
The multi contains an extra final. Also other caches around this neighbourhood.
If you like it a little bit shorter:
http://www.geocaching.com/seek/cache_details.aspx?guid=d762909b-5590-4823-9b7b-c8d1f96389e6
Nice walk in the regional park of turnhout.
A bit more crowdy though
Have Fun Caching !
Have fun !