Originally posted by evilwillhunting:

Get a whole mess of rocks. Like a few hundred.

Ready your hoe.

In a circle around your base, raise the rocks about four levels, except for one place where its only two high (where you can hop up to re-enter).

Voila. You now can ignore any sieges forever. When they show up just wait them out and you'll be perfectly safe.

Small thing, but with good stamina you can run straight up most raised terrain walls even all the way to max height. I do this for my outposts but my main base is handicapped accessible (cart) these days. It depends on how easy it is for you to fight off the raid. If its a tough high risk fight, block it off. If they are easy for you, doesn't matter so much.