One tour group jutted up against another on a recent, cold Wednesday at Auschwitz, the German Nazi concentration and death camp complex.
Guides shuffled guests through the crematorium, the torture block, barracks and displays, like human hair shorn from prisoners after their death in gas chambers.
Now known as the Auschwitz-Birkenau Memorial and Museum, it is about 70 kilometres (43 miles) west of Krakow. In 2019, about 2.3 million visitors came here – a record.
Press Officer Pawel Sawicki says he wants to reach millions more – online, which he does via the official @AuschwitzMuseum Twitter account.
Sawicki works out of what once was the pharmacy of the German Schutzstaffel, the SS force that guarded the camp. He lifts the blinds and points to the barbed wire in his view.
Throughout the day, he publishes tweets, usually about the people who died here at Auschwitz.
The Nazis murdered at least 1.1. million people here, mostly Jews, but also non-Jewish Poles, gay men, members of the Roma ethnic group, Soviet prisoners and Jehovah’s Witnesses.