This simple swap will restore the terrain. If you find the terrain changes are not your cup of tea, you can restore the original RTW terrain by renaming descr_geography.db something else, and changing descr_geography.db.RTW to the 'proper' name of descr_geography.db. Note: the original descr_geography.db file is included in RS 1.6 and named descr_geography.db.RTW. NOTE: If the version you see is 1.0, 1.1, or 1.2 this will require you to install patch 1.3 first
Check your version of RTW by running Rome Total War (not BI if installed) and looking in the top right of the Options menu.(Barbarian Invasion is not necessary for this mod to work). Roma Surrectum Build 1.6 is a full conversion of RTW built to run on RTW version 1.5. WARNING: This mod will cause Vanilla, BI and Alexander not to work and is not compatible with any other mod “Ecce, Roma Surrectum (Behold, Rome Arises)– Building an Empire” v1.6a.