Hoan Kiem Lake & Ngoc Son Temple
Hoan Kiem Lake, or 'Lake of the Returned Sword', is the heart of Hanoi. Legend says a magical sword was given to Emperor Le Loi, which he later returned to a giant turtle in the lake. Ngoc Son Temple sits on a small island in the lake, accessible by the iconic Huc Bridge. It's a beautiful spot for a morning walk, and I think you'll find the atmosphere surprisingly peaceful amidst the city bustle. This is definitely one of the best things to do in Hanoi.
Insider Tip
Visit early in the morning (around 7:30 AM) to see locals practicing Tai Chi.