This was a really fun activity that I came up with for all of my geography classes (from Key Stage 2 to IGCSE) whilst teaching in the former Soviet Republic of Georgia. I had no idea whether the Queen (or her office!) would actually reply, but the students were delighted to receive a letter along with information about the Royal family, and of course a letter with the Buckingham Palace postal mark on it! This was hung in pride of place in the school entrance, much to the delight of visiting parents.
The activity is based on the National Curriculum for geography, and how to address an envelope, along with understanding the differences between country, county, postal code, and street name. But is equally beneficial as part of a literacy lesson, introducing yourself to a stranger, or for talking about the cultural differences, or being on holiday. For example, Georgia has no postmen or women, and there are no post boxes, whereas Britain has red post boxes, and our stamp has an image of the Queen's head on it.
The worksheet itself is hand drawn as I had no resources in Georgia, other than access to a photocopier in the city. I hope you will enjoy this activity as much as we did. I sent each class's letters in one envelope, we heard back a month or so later, mainly due to Georgia not really having a postal system at that time.
Please leave me a review and I will send you any other resource of your choice for free (contact me: firstname.lastname@example.org). Check out my other resources at my shop: https://www.tes.com/teaching-resources/shop/sarah277
Let me know if you have any resource requests and I will tailor make a resource for you.