According to legend, Charlemagne discovered the graves of the city's martyrs Felix and Regula and had a church built as a choristers' cloister on the spot. Construction work on the present building began around 1100.
In the first half of the 16th century, Grossmünster Church was the starting point of the Swiss-German Reformation led by Huldrych Zwingli and Heinrich Bullinger. The theological college then annexed to the cloister became the germinal cell of what is now the University of Zürich.

Worth visiting:
Church windows of Sigmar Polke
Romanesque crypt, Romanesque capitals in the church and cloister.
Choir window by Augusto Giacometti (1932),
bronze doors by Otto Münch (1935 and 1950),
Reformation Museum in the cloister (open Mon-Fri 9 am -6 pm, closed on weekends).

Opening hours of Grossmünster Church
March-October, 9 am -6 pm (Mon-Sat)
November-February, 10 am - 5 pm (Mon-Sat)
Sundays after the church service
Changes due to current events possible, so please call ahead to confirm.

Opening hours of the Karlsturm tower
March-October, 10 am -5 pm (Mon-Sat), Sundays 12:30 pm-5:30 pm
November-February, 10 am -4:30 pm (Mon-Sat), Sundays 12:30 pm - 4:30 pm
Changes due to current events possible, so please call ahead to confirm.

Tours

• Public tours of the Grossmünster: At 11:30 am on the second Sunday of the month, there is a one-hour public tour of Grossmünster Church, including a visit to the cloister, starting at the main entrance. Language: German. The tour costs CHF 5.00 per person.
• Spiritual night-time tours of Grossmünster Church: At 10 pm on the last Friday of the month, there is a one-hour public tour of Grossmünster Church, during which visitors, accompanied by a knowledgeable guide, will have an opportunity not only to discover the unique atmosphere of the church interior, but also to enjoy panoramic views of Zürich at night from the church tower.
  The tour starts at the main entrance and is free of charge.