Shah Jahan built octagonal tower or Musamman Burj inside the Agra fort for his wife, Mumtaz Mahal. It was here that Shah Jahan spent last seven years of his life imprisoned by his son Aurangzeb. The tower is considered to provide one of the best views of the Taj. This exquisitely carved tower is close to the Diwan-i- Khas. But today the pollution has reduced the visibility and the tower is in bad shape. The two-storied Musamman Burz or the Octagonal Tower, adjoining the Dewan-i-Khas was specially built and decked with jewels by Shahjahan for the use of his wife Begum Mumtaj. The mosaic and the latticework of the ornamented Burz are of extraordinary beauty. The Khas Mahal, the Emperor's lounge and bedchamber are on the south and quite close to it is the rather small white marble Nagina Masjid with three round domes on its top, meant to be used by the ladies of the Mughal harem. Machchhi Bhawan, the aquarium is on the southeast of Nagina Masjid. There is also a Hindu Temple here.