For the first time ever, the public will have the opportunity to view the profane medieval frescoes of Rome’s Santi Quattro Coronate basilica, rediscovered during the course of a decade-long conservation project that started in 1996, reports the Art Newspaper. For centuries, the painting had been hidden beneath layers of plaster and paint, possibly applied during the plague of 1348.

Since the 16th century, Santi Quattro Coronate, built in the fourth or fifth centuries, has been the home of a group of Augustinian nuns. Now, visitors will be welcome on two days each month, by appointment only, thanks to a new access route that preserves the nuns’ privacy while admitting the public directly to the Gothic Hall on the first floor of the basilica complex’s Torre Maggiore building.

In an expansion of the recent trend that has seen private companies ponying up to fund restorations of major Italian public monuments such as Rome’s Trevi Fountain (Fendi), Spanish Steps (Bulgari), and Colosseum (Tod’s), the project was paid for by a $201,000 grant from Arcus, a private company backed by the Italian culture ministry. Currently, Rome’s Egyptian-style Pyramid of Cestius (circa 12 BC) is also being worked on thanks to a donation from Japanese businessman Yuzo Yagi.

The Santi Quattro Coronate paintings, which date to the 13th century, are significant as the country’s most important cycle of profane medieval frescoes. While the paintings do feature some of the saints, the majority of the images are non-religious in nature, depicting such secular themes as the seasons, the virtues, the Zodiac, the liberal arts, and constellations. It’s no “Nikasitimos was here mounting Timiona,” as reads the world’s oldest erotic graffiti (recently reported by artnet News), but the subject matter is still pretty daring for a group of medieval nuns.

The hall and its frescoes are next open to the public on September 9 and 10, and October 14 and 15, with future dates still to be announced. The convent will admit up to 20 people on the hour from 8:30 to 4:30, except at 1:30, which is presumably the designated staff lunch break. Hourly guided tours will take place in Italian beginning at 9:30, and are also available by request in English and French for a minimum of eight people. Admission is €10 ($13.40).