Another nice excursion you can do is a day visit to Ninh Binh, where you can visit the Tam Coc cave. In the outskirts of Hanoi there are some nice pagodas, the most famous of them is the Perfume Pagoda.
An area not far from Hanoi you should not miss is Halong Bay, one of Asia's most beautiful natural wonders. You will need two or three days to visit Halong Bay and its island.
