The Fifth and Sixth Hills - Strolling Through Istanbul: The Classic Guide to the City - page 262

About 150 metres along this street we see on the left the Greek
church of the Panaghia Uranon, Our Lady of the Heavens. This
church is Byzantine in foundation, but the structure in its present
form is due to a complete rebuilding in 1843. Some architectural
fragments of the Byzantine church can be seen built into the walls
of the church.
KEFELİ MESCİDİ
A little farther along we turn right on Draman Caddesi, where almost
immediately on our right we come to a Byzantine building converted
into a mosque. This is known as Kefeli Camii or sometimes as Kevevi
Camii; it is in fairly good condition and is still in use. It is a long
narrow building with two rows of windows and a wooden roof;
the entrance is now in the middle of the west wall. As in the cases
mentioned above, the identiication is much in dispute; it may have
belonged to the Monastery of the Prodromos in Petra, and it was
probably not a church but a refectory, since it has but one apse and
is oriented north instead of east. It has been dated variously from the
ninth to the twelfth centuries.
BOĞDAN SARAY
If on leaving Kefeli Camii we turn right and take the first street to
the left almost opposite the mosque, and then again the first on the
left, we soon come to the ruined crypt of a tiny Byzantine building.
It goes by the lordly name of Boğdan Saray, or Moldavian Palace,
because from the sixteenth to the eighteenth century it served as the
private chapel attached to the palace of the Hospodars of Moldovia.
It appears to date from the twelfth or thirteenth century and to have
been dedicated to St. Nicholas, but it was probably not originally a
church, since it is oriented to the north, but a funerary chapel. And
indeed three sarcophagi were found in the crypt during some very
clandestine (and unpublished) excavations carried out in 1918. At
the beginning of the present century it had an upper storey with a
dome, but this has now disappeared. All that remains is a tiny barrel-
vaulted room, with a pretty little apse at the end.