Rhegion (modern Küçükçekmece) was a western suburb of Constantinople in Thrace on Küçükçekmece Lake. Justinian built a bridge across the Myrmex, which connected Küçükçekmece Lake to the Marmara Sea. Its port and Church of Sts. Stratonikos and Kallinikos were damaged in the earthquake of 557. Because of its proximity to Constantinople, Rhegion was often involved in the political strife of the capital: thus the Green faction welcomed Phokas in Rhegion and invited him to Hebdomon. In 1329 people gathered in Rhegion to meet Andronikos II. It was frequently attacked, being burned by Khan Krum in 813 and pillaged by Kalojan pillaged in 1206. In 1261 Alexios Strategopoulos camped at Rhegion before capturing Constantinople. One of the gates of the Theodosian Wall was called Rhegion.
Plan by Mansel
From De Aedificiis by Procopius
“There chances to be a kind of lake very close to this place called Rhegium, into which pour streams that flow from the adjacent uplands. This lake extends as far as the sea so that in the very narrow tongue of land between them they have a common shore. Both sea and lake wash against this shore as their waters roll against its opposite sides, and they bellow against each other as they constantly rush straight on towards one another, sharing a common beach. But when they come very close, they check their flow and turn upon themselves, just as if they had fixed their limits there. However, there is a place where the waters mingle, having a sort of strait between them, and it is uncertain to which of them belongs the water of the strait. Neither does the current of the sea always flow into the lake nor does the lake continuously empty into the sea; but when heavy rains have fallen, and when the south wind has been blowing, the water of the channel seems to flow out from the lake, but if the wind comes from the north, the sea seems to be flooding into the lake. At this point, moreover, the sea is shallow for a considerable distance, with the exception of a very small space where the depth is great. Indeed this is so narrow that it is called Myrmex. The strait which joins the sea and the lake, as I have said, was crossed in ancient times by a wooden bridge, with great danger for those passing that way, because they were often destroyed together with the bridge-timbers if they happened to collapse. But now the Emperor Justinian has carried the bridge on a huge arch built of picked stones, and thus he has made the crossing there free from danger.”
Mimar Sinan Bridge in Kucukcekmece