I was called to fix some parking lot lights. In tracing the circuit - with toner and marking paint - I found a place where the lines seemed to cross. Under the seamless asphalt, I found a junction box.
Now, until recently, there was no reference in the NEC to boxes, or methods, for mounting in the ground. What I found was a single gang "Bell" box, set in a custom-made concrete block. The contractor even bevelled the edges of the block!
Here is another view of the completely excavated block. Please note the UF coming out... it exited the box through a rigid nipple, then got caught up in the pour.