Welcome to GeoCheck. Using this page you can place a link in your cache description on Geocaching.com, which will allow users to check whether their coordinates are correct. This is particularly useful for Mystery or Unknown cache owners.
You can even include a counter in your cache-listing displaying how many correct and incorrect attempts your cache has generated:
As cache-owner you can upload an image and text to display to successful geocachers and list further child waypoints e.g. good nearby parking spots, trailheads etc.