A century ago, some 400 synagogues stood in what is today the Czech Republic. Scores were destroyed in the lead-up to the Second World War, after Nazi Germany occupied the Sudetenland border region, and scores more during the conflict itself. Even more disappeared under the decades of communist rule that followed. A unique project by the Pardubice-based photographer Štěpán Bartoš, entitled Invisible Synagogues, seeks to document all the “blank spaces” left behind.