Well that eliminates some stone options I was planning on, so let's focus on "caged & harnessed." To keep it light, created a portal in Photoshop & printed it out on over-head transparency film. As it turns out, that crap is expensive. I went to the Office Max store & 50 sheets that I could print on were between $50-75... not quite what I wanted to drop on plastic sheets. So, I cruised ebay & found 50 sheets for $15 which was much more my price range.
Now since desktop printers don't print white, I went back with some white paint over some of the lightning bolts to make them more noticeable. These are actually 2 portals printed & set back-to-back. It helps make it less flat, I think. Then, I cut out 2 frames out of street styrene to sandwich them between.
The whole setup will be chained to two pillar-type-things. Basically just a piece of foam-core with more painstakingly cut out styrene on either side.
For some smaller scrolly work about the frame, I set up my fancy-schmancy Cricut machine to do some decorative symbols & glued them on.
I cut out some anchors for the chain to attach to, sliced a slot in the middle of the pylon & then glued them in. Also, the rivets you see are from those iron-on bejeweled letters teenage girls are so found of.
Next up, we have the paint job. Tried to make the symbols on the frame stick out, but that just looked nasty, so I redid them in silver later on.
To base this, I took spackle & smeared it onto my board, dumped on some liberated gravel, & then dumped on sand. The gravel I found was bigger than I was looking for, but it turned out alright.
I did some quick painting to get the basic background for my grass & dirt, then brushed on some patches of PVA glue that I sprinkled with a mixture of cinnamon & some other spices to look like dirt.
I covered the ground with my 'dump jar' of turf & flock and got the portal suspended. I found that chain on the clearance rack at Michaels. It ended up working pretty well here.
Finally to add some more variety to the landscape, I added some tufts & small pieces of sheet moss.
And that's it, my friends! One sorcerous portal for all your trans-dimensional travel needs.