How to make a bench area on raised Patio

[Green Goblin]

I have a two level patio. The raised level is 18" higher than the other. It currently has wood timbers that they want to get rid of which make up the retaining wall. I am going to install a modular block retaining wall in their place. One side of the wall that ran perpendicular to the house had a raised wooden bench connected to the retaining timbers.

My idea was to take the retaining wall up into a freestanding wall then cap it for a seating area. Their concern is their grandchildren falling over it. How can I build something that can be a seating area but also have some sort of back to it to prevent a child from going over it?

Another question is how sturdy would a wrought iron railing attached to the top of paver/cap of the retaining wall be?

Any ideas that I'm not considering? Any pictures of something like this?

[YardPro]

for a freestanding wall look at keystone countyr manor, or ep henry.

the main thing is that they need to be double sided

[Green Goblin]

I know how to put up a freestanding. What I am trying to figure out is how to put in some sort of backing to it so that a kid doesn't topple over.

[mbella]

Build it twice as deep as you usually would. On the back half, continue the double sided above the front half as far as you like. This will give you a back to your bench seat. Glue each block and cap it.