I'd like to build a retaining wall along the back of my property. There's a steep slope that's impossible to mow and is making it very hard to fence in properly. I'd like a natural stone look without breaking the bank. I've seen some companys that offer molds where you can make your own concrete 'rocks' and have also heard of people going to rock quarries and getting their own stone. Does anyone know which would be the most cost effective? Has anyone used these molds before and knows how hard it is to make the 'stones' with them. The area is about 500 feet long so I want to use as big a stones as possible.