The Church of Sts Cyril & Methodius houses a moving memorial to the seven Czech paratroopers who were involved in the assassination of Reichsprotektor Reinhard Heydrich in 1942, with an exhibit and video about Nazi persecution of the Czechs. The church appeared in the 1975 movie based on the assassination, Operation Daybreak.
The paratroopers hid in the church's crypt for three weeks after the killing, until their hiding place was betrayed by the Czech traitor Karel Čurda. The Germans besieged the church, first attempting to smoke the paratroopers out and then flooding the crypt with fire hoses. Three paratroopers were killed in the ensuing fight; the other four took their own lives rather than surrender to the Germans.
In the crypt itself you can still see the bullet marks and shrapnel scars on the walls, and signs of the paratroopers’ last desperate efforts to dig an escape tunnel to the sewer under the street. On the Resslova side of the church, the narrow gap in the wall of the crypt where the Germans inserted their fire hoses is still pitted with bullet marks.
