The venue for the 1st race in the series is the rolling grassland and rocky ridges of Rohan. This map is based on an area in New Zealand I once ran on which looks like the Rohan country in the LOTR films.
Sas, yes maybe the open with scattered trees could be faster. I don't think its possible to change that without re-converting so you will have to put up with it for the next races.
@Billo. You can actually. Either select everything in tri-mode, or you can also select tris by forest type. then change the speed (can even change it relative like +2 in case you have selected stuff with different speeds-