A bastle house is a kind of castle that was built to help protect the people who lived in it from attackers. It was made of very thick, strong walls and had one entrance that could be barred from the inside. Inside the walls, there would be one large room with a fireplace and plenty of windows so that the people living in it could keep an eye out for any attackers. The walls around the house were also very high, so it would be difficult for attackers to reach the door.