Along the Golden Horn - Strolling Through Istanbul: The Classic Guide to the City - page 320

them one must be equipped with a flashlight. The penetralia consist
of two nearly parallel walls some 60 metres long, the space between
which varies from 8 to 12 metres in width, being divided by arched
cross-walls into three storeys of compartments - 42 in all. Since the
wooden floors have long since decayed, these vast dungeons give an
impression of immense height. From this passage one can enter the
towers of Isaac Angelus and Anemas, where a ramp leads down to
a small entrance at the foot of the wall; here one gets a good view
of the enormous towers from the outside and notices the curious
“counterfort” by which they were surrounded at the bottom.
TOKLU DEDE MESCİDİ
Leaving the Palace of Blachernae, we retrace our steps for a short way
down the Street of the Dervish's Son; then we take the first left along
a winding lane that leads us downhill towards the Golden Horn. A
little way along, at a bend in the road to the right, there were once
visible the fragmentary remains of a tiny Byzantine church. Not many
years ago the apse and two walls of the church were still standing and
traces of frescoes could still be discerned within. But since then one
wall and the apse have disappeared and all that remains is the south
wall, which now forms part of a house. The church was converted
into a mosque after the Conquest and called Toklu Dede Mescidi,
in honour of Toklu Ibrahim Dede, a companion of the Prophet who
died in the first Arab siege of the city in 673. We mention this now
almost unidentifiable wall because a lot has been written about it by
the Byzantinists - but to no great purpose. It used to be identified
as the church of St. Thecla, founded by a daughter of Theophilus
the Unfortunate in the ninth century, but this ascription has now
become unfashionable; the arguments both for and against it, or
any other identiication, are exceedingly tenuous. Undoubtedly the
remaining wall of the church will soon disappear as well; then the
tedious arguments can at last be laid to rest.
A few feet farther on, the lane comes to an end and we find ourselves
once more on the main coast road. We are now on the site of the last
sea-gate in the walls along the Horn, the Porta Kiliomene, of which
not a trace remains. To our left on the avenue, we see the last stretch