Many animals are natural architects. They build their homes with the materials they have around them, and the structures incorporate seamlessly with their surroundings. Humans have different architectural styles, in which structures stand apart from nature, and land is divided into privately owned spaces. In a sense, people have developed their own environment with the creation of cities. Buildings and homes diverge drastically from the landscapes that existed before. In constructing these buildings, habitats are destroyed, the air gets polluted, and waste congregates. However, there are many structures that took environmental concerns into consideration. These structures demonstrate unity with the natural world, and some are even measures to both cope with and improve the environment.