This bell tower is part of a complex of buildings named the Royal College of Maidens Nobles. This educational institution for unwed women was founded by Cardinal Juan Martínez Silíceo in 1551. His mausoleum is in the adjacent, elegant church. The buildings were extensively renovated and expanded several times since the 16th century yet the architectural integrity of the oldest ones was maintained. In 1998, Real Colegio de Doncellas Nobles became a residence for female university students. In 2016, the historical facility opened for tours for the first time.