Return to the Roots or RttR is an open source add-on type of remake of The Settlers II. This means it requires the original game files in order to work as Ubisoft did not give Settlers Freaks (the group developing RttR) a permission to redistribute the files. This means you need The Settlers II: Gold Edition for RttR to work.
Here are some screenshots of my worldmap which is 1024x660 large - the largest map settlersII has ever seen!