It is true that Poser does not have any landscape creation capabilities. However, if you do indoor scenes, you can do nicely with the rather primitive modelling capabilities in Poser. Create some walls with the primitives, apply a nice texture to them (available as free stuff) and add some furniture props (also possible to find as free stuff). There are also very nice full interiors made for Poser, mostly as commercial items, that will give you plenty of possibilities. If you find a free copy of Poser 3, please be aware of the fact that the leap to Poser 4 was huge!