Words can do little justice to the scenery that awaits travelers to Ha Long Bay, a UNESCO World Heritage site. Hundreds of forested limestone karst formations rise from emerald-green waters, looking like slumbering creatures ready to stir. The islands have a legend behind them: The gods sent a family of dragons to assist Vietnam's emperors in repelling invaders, and the creatures spat out jewels and pieces of jade that turned into the islands. Many tourists come here on a day trip from Hanoi that involves an early departure, a three-hour bus ride to the ferry terminal, and a four-hour cruise along with scores of other boats before a transfer back to the capital. To truly appreciate the natural beauty with a modicum of solitude, take an overnight cruise—waking in the morning to the sight of the mist-shrouded peaks without the distraction of tons of other boats (and their gawking passengers) is unforgettable.