请为以下段落选择合适的主旨大意。 2. Houses are like sentinels(哨兵) in the plain, old keepers of the weather watch. There, in a very little while, wood takes on the appearance of great age. All colors wear soon away in the wind and rain, and then the wood is burned gray and the grain(纹理) appears and the nails turn red with rust. The windowpanes are black and opaque; you imagine there is nothing within, and indeed there are many ghosts, bones given up to the land. They stand here and there against the sky, and you approach(靠近) them for a longer time than you expect. They belong in the distance; it is their domain(领地). (Para. 11)