Time Out says
One of Charles III's scientific institutions, the Observatory was completed after his death in 1790. Beautifully proportioned, it's Madrid's finest neo-classical building, designed by Juan de Villanueva. It still contains a working telescope, which can only be seen by prior request. One room is also open to the public, but only on Fridays while the building undergoes renovation.
Alfonso XII 3
|Transport:||Atocha (M: L1)|
|Price:||€5; free under-3s.|
|Opening hours:||Visits require prior booking. Fri 4.30pm; Sat noon and 4.30pm; Sun noon. Jun-Sep afternoon visits at 5.30pm; Jul-Sep Sat visits only at noon.|