I have these 2 things, they are liners for culverts...
They are about 2 ft square with an open center (think of a square O) HEAVY, about 40 lbs each Id guess, made of concrete but the sides are smooth. Id like to mo them for planters, but they wouldnt have a bottom since they are open. something like that should bear the weight, wouldnt tip and would mo easily. Look at someplace that sells premade concrete forms for drains and posts and things.

I mosaiced cement blocks. got the idea from slowmedown and Flagtruck ( I think) to use plates or big tiles over the holes

Shrty! Love those!!! Great job! Great idea with the plates!!!!

Thanks!
Unfortunately, I can not use cement block for this project as you can't put the barrel on an upended block - way too narrow. Great for a pot stand (I like yours!!) but won't work for the barrel.
Culvert forms are a good idea. I have never seen a place here that makes them!

What about using a group of four or more cement blocks laying on their sides instead of on ends. That way you can make it as hi as you need it and still would be stable. The sides can be finished however you want. The ends would be kind of hidden, but could be painted with flowers etc. Or you could put small little creatures in this space peaking out of their hideaway.
These spaces also could be used maybe for a little gnome house. Just a couple of ideas since the cement blocks would be a good choice because of the weight they would be supporting.

Kathy