Concierge.com's insider take:
How exceptional is Hoi An? So special that by tacit agreement among all combatants, it wasn't attacked during the Vietnam War. That neutrality left the town, a trading port dating from the 15th century, in a state of preservation worthy enough to gain it UNESCO World Heritage status. The gracious buildings and streets show a variety of architectural influences, especially from China and Japan; the town prospered in the 17th and 18th centuries, when merchants from as far afield as India and Holland set up emporiums. But business literally dried up in the 19th century, when silting clogged the Thu Bon River. The port shifted to Da Nang, 20 miles up the coast, and Hoi An became a near-forgotten backwater. With a medieval cityscape untouched by Vietnam's go-go economy, it easily doubled for 1950s Cholon, Saigon's Chinese quarter, in the film adaptation of Graham Greene's classic novel, The Quiet American.
Also famed for its custom tailors, the tourist-oriented old quarter is laid-back and pedestrian-friendly, with a ban on cars, touts, and street peddlers. For many of the sites you'll need to buy a 70,000 Vietnamese dong entrance ticket (about $4.50), which entitles visitors to a selection of museums, historic houses like the Tran Family Chapel (built in 1802 and still privately owned), and pagodalike community halls erected by ancient expats from Fujian, Canton, and other Chinese provinces. Take time also to just wander the streets and admire the rows of "yin and yang" (concave and convex) roof tiles, fishermen along the colorful waterfront, and quirky local enterprises like the Hoi An Department of Managing and Gathering Swallow's Nests (53 Nguyen Thai Hoc St.), which heads to the Cham Islands twice a year to gather the main ingredient for bird's nest soup.