Emyn Muil map.
Emyn Muil is a mainly inhospitable land. Not far from here Sam and Frodo tamed Gollum.
In this map there are 2 start positions and 2 areas coming off them which are easily blockable incase your starting position falls. In the middle there are 2 areas which, while having no gate, should be fairly easy to defend. There are spider lairs, outposts, ruined towers, helms deep wall sections and signal fires in these areas. Or, if you are tactical or just plain sneaky you can use one of the paths which, although longer, take you around the defendable areas.
Hope you Enjoy