Kaunas Fortress, Lithuania

In 1882, the Russian Empire aimed to build nine fortresses across Lithuania. The final base, Kaunas Fortress, was finished just before World War I. Kaunas entered the war when the German forces attacked in 1915. After World War I ended, Kaunas Fortress was left completely abandoned for years.

However, the fort received attention when Nazi Germany overtook Lithuania during World War II. They used Kaunas Fortress to detain, interrogate, and execute tens of thousands of Holocaust victims. The fort remains as an eerie, grass-covered reminder of the tragedy.