We had a large number of pieces of 1 inch wide slabs, just right for making a crevice garden which are the latest thing in growing alpines.
I had to dig down a fair way to get the first piece in to the correct level.
Second piece put in on the end of the first, not as tall a piece so that the crevice slopes down to ground level.
Second row about 2 inches away from the first and slightly lower.
Third row, lower again and a slightly bigger gap.
More rows, longer to give some shape, but lower so that the area will slope down to the ground.
The final row, shortest of all.
Filled with gritty compost.
Covered with the same gravel as the rest of the area. When the compost has settled I will plant it up.