From Haghia Sophia to Beyazit Square - Strolling Through Istanbul: The Classic Guide to the City - page 139

Continuing along the left side of Divan Yolu, on the next block
we pass the Galeri Kayseri, the best book shop in the city for works in
English on Istanbul and other places in Turkey.
At the next corner we turn left on Piyer Loti Caddesi, named for
the French writer Pierre Loti. At the end of the block and on the right
we come to the Eminönü Belediye Başbakanlığı building, the Town
Hall of the Eminönü district, which has now been merged with the
Fatih district, the two together comprising the whole of the old city.
A door to the right of the main entrance has a sign indicating the
entrance to the Theodosius Cistern, another of the city's late Roman
subterranean reservoirs. The cistern measures 42.5 by 25 metres; its
roof of brick domes in the usual herringbone design is supported by
32 columns of white marble in four rows of eight each, with some
capitals of the the Corinthian order and others Doric, undoubtedly
reused from older structures. The cistern is believed to have been
built during the reign of Theodosius II (r. 408-50) by his sister
Pulcheria, who would later marry her brother's successor Marcian
(r. 450-7). The cistern was summarily restored and opened to the
public in 1994.
We once again turn to Divan Yolu. Then on the next block we
see on the right side of the avenue the rather heavy türbe of Sultan
Mahmut II (r. 1808-39) and its long garden wall. Mahmut died
in 1839 and his türbe is in the then popular Empire style, a little
pompous and formal. Here also are buried sultans Abül Aziz (r.
1861-76) and Abdül Hamit II (r. 1876-1909), together with a large
number of imperial consorts and princes.
THE KÖPRÜLÜ COMPLEX
Directly opposite the türbe of Mahmut II, on the left side of Divan
Yolu, we see an elegant Ottoman library of the seventeenth century.
This is one of the buildings of the Köprülü külliyesi, whose other
institutions we will presently see in the immediate neighbourhood.
These buildings were erected in the years 1659-60 by two members
of the illustrious Köprülü family, Mehmet Paşa and his son Fazıl
Ahmet Paşa. The Köprülü are generally considered to be the most
distinguished family in the whole history of the Ottoman Empire.