The zip file in this download is named 'Luo-TFOTS.zip' and contains a map file named 'Luo-TFOTS.map'. 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.
This is the original Luo Island map from "The Fall of the Song" custom campaign (released in 2009). It is 'enormous' size and has a temperate climate. No extra modifications have been made to this map for Open Play. This map is an adaptation of coastal topography that is common in some areas of southern China and Thailand.