As temperatures plunged, some sought warmth by fire pits, while others embraced the winter air with midnight walks and late-night street food outings.

Hanoi in Vietnam is known for its incredible food, buzzing nightlife and plenty of culture - but it's also one of the most polluted cities in the world.

From French colonial architecture to tasty street food and chic boutiques, Vietnam's capital will surprise you. Few Asian cities seduce visitors the way Hanoi does. With its romantic blend of "old ...