I've got a problem with a small commercial landscape I just finished. The building has a couple of large masonry planters integrated into the front of the building. They measure about 4' all, and about 5' square. Also, they have some runoff from the vestibule on the front of the building that needs to be taken care of. Their original purpose was as planters, but... they've been used as ashtrays more than anything else. The new owner told me he'd like to have about the front 1' made into some type of ashtray, and the remaining big part at the back planted with plants. (I asked him about the modern "butt can" things that say "Put 'em here". He said he had tried that and they had been stolen.) So, I did this: I dug a hole down to almost the bottoms of each planter, and filled it with gravel in landscape fabric. I placed a catch basin grate on top, and LAID RECTANGULAR STONE AROUND THE GRATE TO HOLD IT IN PLACE. I also used the stone as a border between the front 1' and the back part, which is now planted in juniper and a landscape light. This is where it gets interesting. A few nights ago some little punk assholes picked up one of my stones and used it to bust out a window and burglarize the place. Fortunately, they got caught and are probably on their way to getting acquainted with Leon and Bubba at the State Prison. Any suggestions on how to retrofit these planters to prevent this happening again? I wouldn't know how to mortar this stuff in or whatever because it's just sitting on sand. I've thought of having a craftsman make some wrought-iron grates to put over it, but I'm not sure that's going to have a good aesthetic effect. If pictures would help anyone get me some ideas, I'll send them in a private email. Thanks.