Google Earth
Google Earth is a tool for Mac, Windows and Android that displays a 3D view of the world based on satellite imagery. It also allows to create and display KML waypoints and tracks directly over the 3D world.
Using Google Earth makes it easier to find canyons and caves, since flying over terrain provides a good way to visually locate waterfalls, rocky outcrops, sinkholes and other such features.
There are some Google Earth extensions that can be very helpful for locating such new locations. Below are the ones we know about, if you know of any other cool extension please feel free to add to this section.
Historical Imagery[edit]
The clock icon on the top bar gives easy access to past imagery through a time control that displays the date the imagery was taken. It may be very interesting to see an area under different lighting conditions to pick up slot canyons or shaded waterfalls but it may also be very useful to compare the area conditions in different seasons to get an idea of when the area might be high flow or low flow.
Gallery Layer[edit]
The Gallery Layer integrates a number of different POI providers. Historical Earthquake epicenters and Commercial Panoramas up for sale might not be very interesting, but live Webcam locations and Hiking routes from Everytrail, Trimble and WikiLoc might be quite useful to find easy approach and exit to a new location. Clicking on any POI will open a window with more information and often a link to display the route directly in Google Earth.
Maps Overlays[edit]
More maps overlays are also available from http://ge-map-overlays.appspot.com/