The three Hangover films keep coming back to Caesars Palace: the friends check in and toast on its roof in the first film, and Mr. Chow jumps from a penthouse balcony in the third. Start there: the lobby and valet drive are real, and the four walk to the lift in the corridor of the Augustus Tower. The Bellagio is ten minutes away on foot, and Madame Tussauds at the Venetian has a copy of the wrecked suite.
The rest of Las Vegas needs a taxi or the Deuce bus. North of the Strip, the Bungalows Hostel once wore the fake front of the Best Little Chapel; downtown, Atomic Liquors and the Plaza, where Chow's parachute flight ends, are a short walk apart. At the south end of the Strip is the corner where Chow jumps out of the trunk. For Jean Dry Lake, about 40 minutes south, you need a car and water. The Riviera and the motel used for Jade's flat have been demolished.
The second film moves to Thailand. In Bangkok, have a sunset drink at the Sky Bar (dress smart), walk the Chinatown lane of Soi Phiphaksa 1, see the neon of Soi Cowboy at night, and keep most of a day for the monastery at Muang Boran. Stu's wedding resort, Phulay Bay, is near Krabi, a flight away.