Walrus

I just got a Nile Monitor. He is sitting in his huge enclosure right now burrowing himself. I have yet to get the temps and the humidity and all that up to specs. Just thought I would ask if anybody has one and if they do I was wondering what types of setups they have for them. I was thinking of maybe having one warming pad beneath the enclosure that way when he burrows he can get to it. But as I think about it in the wild this wouldn't be natural. I'm going to set up a row of lights above his cage and tweak the temps for basking above the burrowing soil but I have a feeling he will be spending a lot of his time burrowed. So I thought I would ask what type of set up anybody else has. Thanks.