Zoos, botanical gardens, and arboreta are places where the diversity is life is presented, and often bred, for scientific, conservation, and recreation purposes.
In the U.S., national monuments have been designated by the president in order to conserve at least one unique site for a particular scenic, cultural, environmental, historical or other reason.
National governments create and protect national parks for a variety of reasons, including scenic, environmental, cultural, historical, recreation, scientific or other values.
Land can be named a 'nature preserve' at the local, state or national level. The degree of protection varies by country, but nature reserves are generally designated for conservational purposes.
Protection is not limited to the preceding land designations. Other areas can be granted protection at varying levels and for many different reasons; in some cases environmental protection is just a side benefit.