LUANG PRABANG, Laos -- Rising from a narrow peninsula at the confluence of the Mekong and Nam Khan rivers, Luang Prabang is one of Southeast Asia's most romantic cities. Walkable and virtually traffic-free, imbued with old temples and colonial-era French architecture, the city has been a UNESCO World Heritage Site for more than 30 years. While tourism dictates daily life, the slow charm of communist Laos lingers in cafes, riverside eateries and temple courtyards.