Hoan Kiem Lake, also known as the Lake of the Restored Sword, is a must-visit attraction in Hanoi Old Quarter. It is a beautiful lake located in the heart of the city, surrounded by lush greenery and historical landmarks. Take a leisurely stroll around the lake, enjoy the peaceful atmosphere, and visit the Ngoc Son Temple located on a small island in the lake. The temple is dedicated to the national hero Tran Hung Dao and offers stunning views of the lake and its surroundings.