Originally posted by ErnurWolf:

mostly the motes worked , this last two attacks 1 of these giants was out in the ocean up to his nipples smashing my docks and boats . the other just waded through my moat and it is wide and deep .

The proximity to the sea is a problem. I has this happen with my first castle that was up against the ocean. Trolls will wade through water.
To fix this I had to use my hoe and raise a levy around my base with my mote. This way my moat is continuous and now the trolls cannot get in anymore. It really has to be a continuous moat. Depth has to be deep and steep. If you can walk out of it then they will walk out of it. If you fall in and get trapped they will get trapped. I have never built a bridge personally. I just jump my moat but I havent had a problem since I built the levy.