Urban villages are not regulated by any form of centralised urban planning. Most of them are heavily populated, intensely developed, and lack infrastructure. Some villages' building density is greater than 70%. They are composed of crowded multi-story buildings ranging from three to five (or more) floors, and narrow alleys, which are difficult for vehicles to pass through. Inside villages, it can be dark and damp year round and lighting may have to be kept on even during daylight hours. However, many villages have designated areas at their core which house cultural facilities and examples of historic architecture, while others have special shopping and market streets, sometimes reserved for pedestrians.