For triggering context specific information in a museum, visitor centre, quarry or other small area,
GPS does not provide sufficient resolution.
Instead you require Micro-location as provided by low energy radio beacons.
Smartphones increasingly support this and developers can build apps in which content is
triggered once the user is within a certain range of the 'beacon'.
The beacons themselves are housed in discrete weatherproof enclosures
powered by a lithium battery for 5 years.
Screen shots for an app for Robinswood Hill Geology Trail - release 2016
Ancient landscapes visualised