A place of worship is a specially designed structure or consecrated space where individuals or a group of people such as a congregation come to perform acts of devotion, veneration, or religious study. A building constructed or used for this purpose is sometimes called a house of worship. Temples, churches, synagogues and mosques are examples of structures created for worship. A monastery, particularly for Buddhists, may serve both to house those belonging to religious orders and as a place of worship for visitors. Natural or topographical features may also serve as places of worship, and are considered holy or sacrosanct in some religions; the rituals associated with the Ganges river are an example in Hinduism. Under International Humanitarian Law and the Geneva Conventions, religious buildings are offered special protection, similar to the protection guaranteed hospitals displaying the Red Cross or Red Crescent. These international laws of war bar firing upon or from a religious building. Religious architecture expresses the religious beliefs, aesthetic choices, and economic and technological capacity of those who create or adapt it, and thus places of worship show great variety depending on time and place.