I had a small cinder block as my outside altar. We had a tree come down in the front yard earlier this year and i used parts of it to mark my 9 ft circle. Just finished it tonight. :) I am pretty proud of it. I really have wanted to do this for a long time. I have 3 altars. #1 is in my bedroom for bad weather use, #2 is in the picture with me on the swing. It is for if it's raining, snowing...., #3 is a permanent circle for ritual. They work out really well for me! :)
You all make it worth while to express what is important in your devotion to deity. I am working on a new altar soon, been working on all the boxes we moved in last year and avoided. Till I clear the wall to wall stuff I will put my altar up. And I will make some pictures for on here.