Giant Mountains Map, Poland - Czech Republic 1910

Map taken from page 388
Source: "Northern Germany as far as the Bavarian and Austrian Frontiers; Handbook for Travellers" by Karl Baedeker. Fifteenth Revised Edition. Leipzig, Karl Baedeker; New York, Charles Scribner's Sons 1910

Poland & The New Baltic States 1920

"Poland & The New Baltic States" map from 1920, showing still-undefined borders in the aftermath of World War I before the Peace of Riga
Source: The Peoples Atlas by London Geographical Institute 1920