You needn't have a strong religious faith to enjoy the serene atmosphere of St. Olga Orthodox Cathedral. Ask when the next mass starts or when it's open for general viewing.
This Frantiskovy Lazne principal church is an ideal spot to kick off your day of sightseeing. There's lots to experience close by, like Aquaforum, Komorni Hurka, and Cheb Castle. Take your time at St. Olga Orthodox Cathedral before hitting up these other fine sights.