Las Vegas, officially the City of Las Vegas and often known simply as Vegas, is the 28th-most populated city in the United States, the most populated city in the state of Nevada, and the county seat of Clark County. Las Vegas is situated within Clark County in a basin on the floor of the Mojave Desert and is surrounded by mountain ranges on all sides. Much of the landscape is rocky and arid with desert vegetation and wildlife. It can be subjected to torrential flash floods, although much has been done to mitigate the effects of flash floods through improved drainage systems.