Dear Peter,
I'm glad to hear that you are going to pay a visit to Hanoi next month.
I'm writing to give you some recommendations of Hanoi. As you may know, Hanoi, beside being the capital city of Vietnam, is also known as the city of great beauty spots in my country. When you arrive in Hanoi, you really should visit the The Temple of Literature, which is the symbol of the city. You can get to know more about the history of Hanoi and our tradditional education system.
When it comes to cuisine, Pho is really a must try. It's a speciality of Hanoi. I suggest you should visit "Pho Gia Truyen" store at Bat Dan street, which is, in my opinion, serving with the best quality. Moreover, there are many more good food in Hanoi. I am excited to get you try all of them soon.
One more thing you need to notice is the climate. As Hanoi has the warmer climate than London, you should bring along more light clothes.
There are a lot I want to tell you but I have to stop now.
I am really looking forward to seeing you in Hanoi.
Love,