It is right on the mouth of Mobile bay so it is always damp. Also the brick work is extremely thick and over the years since it was built water has seeped through and leached out some calcium. That is the white you see and it covers many of the walls. I was surprised that there was not more moss growing on the walls than there was. They do not clean the walls as far as I could see. They try to leave it original as much as possible. The only maintenance I could see was a couple of the roofs had been redone to protect the buildings in the middle of the fort. Also during WWI they modified a couple of the areas to put disappearing canons in and they were all concrete. They had to re-coat the top part of the concrete structures to keep them safe and water tight. I have been there many times over the years and I always enjoy it.
