These pieces were bought cheap off eBay, its amazing what you can find by trawling though, looking for Fish Tank items, Reptile Tank items etc. just don't type in wargaming or modelling and you should find a bargain. The best thing about Age of Sigmar is anything is possible so you can pretty much use anything as terrain!
I decided to base them all, so here is 'How I Base' them all.
I used a jigsaw cut 3mm ply base for all the pieces, i applied PVA and corse sand, let this dry and used a watered down PVA to hold it all, I then built up the sand layers to make some rock platforms and sprayed the base Mechanicus Standard Grey. I painted over this with Dryad Bark, and drybrushed with Tyrant Skull before flocking and adding the undergrowth foliage.
I repeated the same process with the rest of the terrain pieces.