Virtual cache
From GeoWiki
A Virtual cache is a type of cache that has no physical container. This is usually done because it would be inappropriate to place a physical container at the location. Reasons for this include:
- it's an environmentally sensitive location
- the land owner does not want caches left there
Logging a virtual caches usually requires proof that you have visited the location, usually in the form of a photograph containing your GPS.
Virtual caches are no longer allowed on Geocaching.com, however they are more than welcome at Geocaching Australia. (Waymarks are Groundspeak's replacement for virtual caches.)