These are a series of pictures that hung on the wall at my parents house for decades and decades. The pictures were taken by my great grand father Ernst von Stackelberg (1868 - 1941). Since he was over 2 meters tall, he had the nickname was Eifel. One of his photos was used in the December 1939 National Geographic article about Estonia.
I will take some time and add the locations to the captions at a later date, I hope. If you know where the locations are, let me know.