Mysterium Fidei

Useful Information

Location: 140-142 St. Christopher's Street, Il-Belt Valletta, Malta.
St. Christopher Street between Republic Street and Strait Street. Opposite the Barrister Hotel.
(35.900030, 14.514495)
Open: All year Mon-Sat 9:30-16:30, Sun, Hol 9:30-16.
Fee: Adults EUR 8, Children (5-9) EUR 4, Children (0-4) free.
Classification: SubterraneaRock Mine SubterraneaCrypt SubterraneaCellar
Light: LightIncandescent Electric Light System
Guided tours: Audiotour: English Malti - Maltese Français - French Español - Spanish Deutsch - German Italiano - Italian Polish - Polski русский - Russian
Address: Mysterium Fidei, Hidden Valletta Ltd., 140-142 St. Christopher's Street, Il-Belt Valletta, Tel: +356-7746-7061, Tel: +356-7708-3138. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1575 St. Catherine’s Monastery founded to care for female orphans.


Mysterium Fidei is the name of secret tunnels located under St. Catherine’s Monastery in the heart of Valletta. It was inaccessible to the public for over four centuries. In 1575, St. Catherine’s Monastery was established in the Casa Vanilla to provide support for female orphans. The building was owned by Marquis Giovanni Vasco Oliviero and his wife, Katerina, who donated it to the church as a gesture of gratitude for their son’s recovery from the plague. But they not only donated the building, they erected the monastery, added an extra floor, and bequeathed all their possessions to the monastery in their will.

The stones which were used to build the monastery were quarried underground on site. In other words, the underground tunnels are actually quarries. But the nuns made an oath to lead a life of prayer, contemplation, and of service, and they chose to lock themselves from the outside world, till death and beyond it. In other words, they did not want their dead bodies to leave the monastery, so they were buried in the underground crypt. In the 1970s, new burial regulations prevented the nuns from being buried within the monastery. However, an exception was later made to allow burial in the crypt, and since then the nuns have been buried here again.

The tours are offered by Hidden Valletta Ltd., a local venture which has specialized in tourism, culture, event organisation and hospitality. They are proud to be Valetta locals. They created a museum in the underground passages which is named Mysterium Fidei Museum. Online booking is recommended, but tickets are also available at the reception desk at the monastery.

The exhibition and the audioguide explain the history from the era of the Knights of St. John, to this day. It also explains everyday life at the monastery and the fascinating secrets hidden within these walls. There are rooms for work, prayer, restraint, and the sleep of death. The museum shows the laundry, sewing rooms, kitchens, and bathrooms. It's not only a story of simple life, there are also "control rooms" where the nuns managed young women who were deemed threats to morality and where they "helped them reform". The museum actually fails to explain how this worked, but it's easy to imagine.