I recently made 8 pieces of area terrain depicting alien tropical jungles for our gaming club. I was inspired by the fluff behind the Xilos Horizon, the scenario of the starter set for Beyond the Gates of Antares, so I wanted to have a jungle table myself!
These were made using various items found in aquarium stores, glued to thick cardboard and then layered with my "dirt texture". Here you see the pieces next to a Concord trooper (28mm), to get a sense of scale:
These pieces have sufficient empty space to accomodate models within the area terrain, and I even added a couple tracks of beaten grass here and there.
This below is probably my favorite piece, a very alien-looking tree:
And here is a pic of the table set for our game of last saturday, featuring the 8 pieces of area terrain, along with the river sections I made a couple years ago (mostly for use on our games of Black Powder).