Bell tower of the Church of San Nicolás de Bari de los Servitas
This church in Madrid de los Austrias (Hapsburg Madrid), declared a national monument in 1947 thanks to its 12th century Mudéjar tower, is the city's oldest building now that the medieval Church of Santa María la Real de la Almudena, which was built on the site of the former Aljama Mosque of Mayrit, has been demolished.