Circular elevated platform facing the Field of Mars from which the emperor would address the army. Built by Valens after his proclamation in 364, its foundational ruins are now ring-fenced by tower blocks.
Tetrapylon denoting the starting point for measuring distances to other cities of the empire.
Tetrapylon at the intersection of the Mese, Constantinople's main street, and the Makros Embolos, the city's great mall.
Constantinian porphyry obelisk where the north and south branches of the Mese met. The famous statue of the Tetrarchs in Venice may well have been pilfered from an adjacent 'Philadelphion' building.
Column of Justinian
Massive brick column covered in bronze, with Justinian on horseback atop it. Nearly as tall as the Hagia Sophia, it stood for a millennium before being taken down after the Ottoman conquest.
Column of Theodosius
50m-tall marble column with spiral reliefs depicting Theodosius's corrective campaigns against the Goths post-Adrianople. Erected in 393 and toppled in the 15th c., its still-visible fragments were reused in the nearby Beyazit Baths.
Likely Palaiologan and part of a larger monastery, little is known about the Roman precursor to this mosque, converted in 1509.
Church of Hagia Euphemia in the Hippodrome
From above, you can just about make out the hexagonal foundations of this 7th c. church, previously a part of the Palace of Antiochos. Identified in the 1930s when its late 13th c. frescoes were uncovered.
Church of Saint John the Baptist
Theodosian shrine for the relic of the saint's head; also where the usurper Phocas was anomalously crowned in 602 before entering the city. A hospital is now in its place.
Church of the Holy Apostles
The city's busiest church housed the tomb of Emperor Constantine and many of his successors. Delapidated by 1453, Fatih Mosque was built over it.
Commissioned by Basil in 876–80, the first monumental church built after the Hagia Sophia. Destroyed by lightning shortly after the conquest.
'Monastery of Christ Pantepoptes'
Eski İmaretiatik Camii
Cross-in-square 11th or 12th c. church, whose identity is contested. More certainly, it became a poor house for the nearby Fatih Mosque under the Ottomans, before itself becoming a mosque.
Only the small octagonal mausoleum —now a mosque— is left of what was once a nunnery complex first mentioned in the 9th c. The exterior is clearly Palaiologan; inside, nothing discernibly Byzantine remains.
Monastery of Saint Andrew in Krisei
Koca Mustafa Paşa Cami
First mentioned in the 8th c., this monastery is thought to have been first dedicated to the Apostle Andrew, then to St. Andrew of Crete in the 13th c. Modified extensively as a mosque, repurposed 5th-6th c. columns and capitals survive inside.
The Byzantine court's main palace until the 11th c., you wouldn't know it from its current state. Named for the bull and lion statues that guarded its shoreline entrance.
The center of imperial administration from 330 to 1081. Only fragments of its foundations and outer walls are visible today.
Palace of Antiochos
One of only two aristocratic houses excavated in the city, this one belonged to an early-5th c. Persian eunuch. Nothing remains of its vast semi-circular portico, but its hexagonal hall became the Church of Hagia Euphemia.
2nd c. BC Roman road through what is now Albania, Macedonia, northern Greece and Thrace to Constantinople. Imperial processions took this final stretch from the Hebdomon to the Porta Aurea into the city.
Sea wall gate apparently breached by Mehmet's forces on May 29th, 1453. Also the spot that faced the left wing of the Venetian fleet during the Latins' failed assault of 1203 and their successful capture of the city in 1204.
The most picturesque part of the remaining Sea Walls, this is only section touching the sea. Named for an eponymous church nearby, the gate represents the southwesternmost tip of the Constantinian city.
Where Ottoman cannon finally breached the Theodosian Walls, and Constantine XI supposedly died defending them. Today's Topkapı ('Cannon Gate') was rebuilt after the siege, becoming the main entrance to Istanbul.
Named for the 'caliga' (boot) workshops inside it, this 'Public Gate' sits between towers 6 and 7 of the Blachernae Walls built under Manuel Komnenos (r. 1143–1180). Famously afforded Constantine XI a final view of Ottoman operations on May 29th, 1453.
Built in different periods, these moatless 12–15 m. high single walls, thicker and with more closely spaced towers than the Theodosian Walls, were connected to them to bring the Palace of Blachernae within the city.
Two rows of 5.7km-long ramparts, 96 towers and 9 main gates make up the most successful defensive system in all of history. Original construction took 9 years beginning c.404.
Started by Septimius Severus c.203 and improved by successive emperors, ended up similar to but lower than the land walls. Breached by the dastardly Fourth Crusade in 1204.