Austin, Texas is where The Last of Us Part I begins: the Prologue of Hometown plays out on outbreak night in September 2013 as Joel, his daughter Sarah and his brother Tommy try to escape the city. It is the only region you visit before the 20-year time skip.
You start as Sarah, exploring the house at night while the news reports go wrong. Control then moves to Joel as Tommy drives the family toward the highway past a burning barn, a jammed interstate and streets full of people running from the infected. After the truck crashes, you carry Sarah through alleys on foot.
Near the highway a soldier under orders opens fire on Joel and Sarah. Tommy kills him, but Sarah is fatally wounded and dies in Joel's arms. Years later Tommy goes back to the empty house and recovers a faded photo of Joel and Sarah.
Boston
Boston, Massachusetts is the first region after the time skip and the city where Ellie grew up. You play The Quarantine Zone and The Outskirts here, and Left Behind's flashbacks with Riley take place in the same city. FEDRA holds the North End as one of the last working quarantine zones in the country.
Lincoln
Lincoln is a small Massachusetts town a few miles from Boston and the setting of Bill's Town, the fourth chapter. Joel and Ellie come here to call in a favor from Bill, a paranoid survivor who has rigged the whole town with traps, because they need a working vehicle.
Pittsburgh
Pittsburgh, Pennsylvania is a former quarantine zone now run by hunters who ambush anyone passing through. Joel and Ellie spend two chapters here, Pittsburgh and The Suburbs, and meet the brothers Henry and Sam. Expect heavy human combat and the largest pile of collectibles in the game.
Salt Lake City
Salt Lake City, Utah is the last stop on Joel and Ellie's search for the Fireflies. It is an abandoned quarantine zone where the Fireflies hold Saint Mary's Hospital, and you play the Bus Depot and The Firefly Lab chapters here in spring 2034.