Twentynine Palms is a city located in San Bernardino County, California, United States. It is situated in the Mojave Desert and is known for its proximity to Joshua Tree National Park. The city is home to the Marine Corps Air Ground Combat Center, which is the largest United States Marine Corps base in the world. Twentynine Palms is also a popular destination for outdoor recreational activities such as hiking, rock climbing, and off-roading. The city has a population of approximately 27,000 residents.