Andrew Hunter's Tandoor oven
Here is a nice tandoor built by Andrew Hunter which looks perfectly at home in the garden. OK let's look at some pictures of how he built his oven. The first two show the pots cut, but notice the notches he has cut into one of the pots.
The reason for the notches was because Andrew's upper pot was the same size as the lower pot. So similar to my very first oven, which meant he didn't have an over hang to rest his skewers on. So he resolved the problem by cutting notches before he assembled the oven. You can see that better in the next picture. Also note in the picture below Andrew is using clay pellets for his insulation. He subsequently told me he found they weren't insulating the pots and too much heat was escaping. He now has vermiculite in to the top, and it is performing brilliantly now.
Then he completed the job by putting decorative slate chips on the top.