I have a couple London Pattern anvils. My favorite anvil and the one I use, is a 4'x4' stump anvil from, Old World Anvils. For a while I even used a 12" piece of 1 1/4" square seated in a hole in a stump, just for the heck of it. I don't use the horn or bottom tools, just hammer and anvil. So, for me, all that is used is the hammer face and about the same area of an anvil. To each their own, but as previously mentioned, there has been an awful lot of ironwork produced throughout history on anvils no bigger than a mans fist.