Angliyskiy Ave., 2B, Saint Petersburg, Russia, 190121
In the film "The Adventures of Sherlock Holmes and Dr. Watson," in the episode "The King of Blackmail," we mainly see the fence of the Milverton estate, along which Watson was walking; the house behind the fence is also present. Previously, this mansion belonged to a Dutch subject, the consul of the Netherlands in St. Petersburg, and entrepreneur Hilze van der Pals, designed by architect Iogansen, built in 1901-02.
In the 1910s, the building housed the Dutch consulate, and later, up to the present time, it has been the Military Commissariat of Leningrad-Petersburg.

On the other side of the fence, where Watson was strolling, there is a kindergarten, which, together with the playground, is now fenced off, so it is impossible to walk along Watson’s path directly, and identical angles cannot be shot without the fence appearing in the frame.

This place is just a few steps from the previous one, although not in the direct line of sight as it was in the film. This second fence adjoins the park of the palace of Grand Duke Alexei Alexandrovich, commander of the Russian fleet and brother of Alexander III.
The greenery on the fence is most likely fake.
Sources:
https://dubikvit.livejournal.com/14256.html
https://www.221b.ru/geo/3-fence2.htm