The zip file in this download is named 'Karakhorum.zip' and contains a map file named 'Karakhorum.map'. This is a modified version of the Karakhorum map from the "Builder for the Great Khans" custom campaign. It is 'enormous' in size, and has an arid climate. It is easier to play than the version in the campaign, because it has been modified to provide more resources.
After downloading the zip file, unzip the map into the folder: \SIERRA\EmperorRotMK\Cities. That will make it available for selection in Open play, or for viewing in the editor.
A list of the modifications that are included on it is as follows:
1. Iron deposits were added to the southeast edge of the map.
2. Salt marshes were added on the northeast edge.
3. A stone quarry was added on the southwest edge.