What is an adf file and how do I open an adf file?
ADF is an internal raster data format used by ESRI products such as ArcGIS, ArcView, and ArcInfo Workstation. It stores spatial data as a binary grid and is one of several ADF files that together comprise the total grid. It is used to represent geographical or other spatial objects such as maps and map features.
Relevant adf file links:How to open adf file on Youtube
How to open adf file on Wikipedia
How to open adf file on Microsoft.com