In these coordinates is a monument to the famous characters of Sir Arthur Conan Doyle as they were embodied in the cinema by Russian actors Vasily Livanov (adopted for this in the Оrder of the British Empire) and Vitaly Solomin.
The cache is located nearby, but not inside the British Embassy ;-) This is in coordinates N55 45.XXX E37 34.XXX. To obtain the missing values, you need to solve a simple puzzle. You have to remember that letters may be numbers or may not be. Good luck!
The сache is a magnetic notebook, without a pencil. It is located in a public place, be careful!