Retaining Wall Safety

by Kelly
(NH)

We are concerned about retaining wall safety.

We have an under garage and two 7 foot large boulder type retaining walls, one to each side of the garage. We also have a 4 yr old and a 2 yr old, and the retaining walls are a danger to them because there is no barrier to keep the children from running across the yard (at first floor level) and falling right off the seven foot wall onto the driveway! No matter how close you watch them, it COULD happen in just a split second.

I don't want to just put a fence there - a safe but potentially ugly solution.

I don't know if I can put shrubs - 1) I don't know if there's enough soil, with the boulder construction of the wall. There's a lot of rock right there, and 2) I'm afraid the shrubs wouldn't be dense enough or high enough to prevent a fall.

Do you have any ideas for an attractive solution for the top of a retaining wall that would also prevent falls from that level. (I'm not talking about kids climbing up and over something, or forcing their way through something - I just want to prevent them from accidentally running too close and tipping over the edge onto the driveway below.)
It would have to be at least a couple feet high and sturdy and without sizable gaps... enough to prevent an accidental fall through. Both retaining walls slope down along their length and taper off at the base of a hill next to the driveway, so they're 7 feet at the top right next to the house, down to basically nothing at the base.

I'd appreciate any ideas!
Kelly