Political and entertainment hub expanded by Constantine to seat 100,000. Its central spina's obelisks and the base of its southern sphendone preserve its faint outline.
Augustaion Aya Sofya Meydanı
Public market and ceremonial square connecting the most important buildings in the city. While still an open square, none of its features survive.
Field of Mars Veliefendi Hipodromu
Vast open space where Valens, Theodosius II, Nikephoros II Phokas and others were acclaimed by the army, and where the emperor was welcomed back from campaign. Now a racetrack.
Baths of Zeuxippos
Blame the Nika Riots of 532 for the destruction of this celebrated 2nd and 3rd c. meeting place. Pieced back together by Justinian, bathing ceased in the 8th c.
Forum of Constantine Mollafenari Mahallesi
Circular square marking the centre of the city after its rededication in 330. Ransacked by the Fourth Crusade in 1204, only the Column of Constantine remains.
Forum of Theodosius Beyazıt Mahallesi
Constantine's Forum Tauri remodeled by Theodosius in 393 after Trajan's Forum in Rome. Only fragments of its Arch of Theodosius remain in situ.
Forum of the Ox
Named for its large hollow bronze statue of an ox, taken from Pergamon, in which various unlucky Constantinopolitans were ceremoniously burned alive. Sadly lost to posterity.
Chora Church Kariye Kilisesi
Literally ἐν τῇ Χώρᾳ 'in the fields' when founded in the 4th c., Chora is famous for its c.1315 mosaics, the finest example of the Palaiologan Renaissance. Now a museum.
Church of Saint John Prodromos Hirâmi Ahmed Paşa Camii
Unmentioned before the conquest but ostensibly from the 12th c., one of the city's 26 churches dedicated to St. John the Baptist. A mosque since 1590.
Church of Saints Sergius and Bacchus Küçük Ayasofya Cami
'Little Hagia Sophia', built c.527-536 in one of Justinian's first acts as Emperor, only a few years before its larger sibling. Now a mosque.
'Church of Saint Theodore' Vefa Kilise Camii
Another cross-in-square 11th or 12th c. church whose original identity is contested. Now a mosque, fragments of its Palaiologan ceiling mosaics are still visible.
'Church of Saint Theodosia' Gül Camii
Its recessed brickwork pointing to the 11th or 12th c., this church's identity is contested, muddied by extensive remodeling over the centuries. Now a mosque.
Church of Theotokos Kyriotissa Kalenderhane Camii
Late 12th c. domed Greek cross church, appropriated by the Latins during their occupation and later assigned to a Dervish sect by Mehmed II. Its interior decoration is largely extant.
Hagia Eirene Aya İrini
The city's first church, commissioned by Constantine, served as the church of the Patriarchate before Hagia Sophia. Never a mosque, it's now a museum.
Hagia Sophia Ayasofya
One of the most influential buildings of all time, Justinian's (and architects Anthemius of Tralles and Isidore of Miletus's) finest legacy stands resplendent 15 centuries on.
Myrelaion Church Mesih Paşa Camii
Mortuary chapel built adjacent to the Myrelaion Rotunda for Romanos Lekapenos c.920. It's unclear whether he ever did come to rest here. Now a mosque.
Pammakaristos Church Fethiye Camii
A supposedly Komnenian church (1081-1185), with a Palaiologan side-chapel. A mosque since 1591 and a museum since 2006, mid-20th c. restoration has brought its Byzantine mosaics back to life.
Church of Saint Polyeuctus Aziz Polieuktos Kilisesi Kalıntıları
The city's largest church before Hagia Sophia. In ruins since the 11th c., two of its ornate columns are now outside St. Mark's Basilica in Venice, misnamed 'the Pillars of Acre'.
Church of Theotokos Chalkoprateia Acem Aga Mescidi
5th c. church that was briefly the patriarchal seat (532-537) while the current Hagia Sophia was being built. Associated foundations are still visible in the basement of the Zeynep Sultan Hotel.
Church of the Holy Apostles Fatih Camii
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.
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.
Commissioned by Basil in 876–80, the first monumental church built after the Hagia Sophia. Destroyed by lightning shortly after the conquest.
Lips Monastery Molla Fenâri Îsâ Câmîi
A North Church (built in 907 by Constantine Lips, an aristocrat) and a late 13th c. South Church make up what is now a mosque closed for restoration work.
'Monastery Mosque' Manastır Mescidi
Likely the Palaiologan chapel of a larger monastic complex, dedication unknown. Now a bus garage's private mosque with pretty Byzantine masonry and columns.
Monastery of Christ Pantokrator Zeyrek Camii
Archetypal Middle-Byzantine monastic complex which became the mausoleum of the Komnenos and Palaiologos dynasties. Now a recently-restored mosque.
'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.
Monastery of Christ Philanthropos Filantropos Kilisesi Kalıntıları
A monastery and convent whose 14th c. incarnation was one of the largest monastic complexes in the city. The remaining substructure is largely unexcavated.
Stoudios Monastery İmrahor İlyasbey Anıtı
Major monastery founded in the 5th c. and dedicated to St. John the Baptist. Its main basilica is still standing, roofless, with elaborate flooring exposed to the elements.
Column of the Goths Gotlar Sütunu
Column commemorating a 3rd or 4th c. victory over the Goths.
Column of Marcian Kıztaşı
Column dedicated to the Emperor Marcian (r.450-57), erected by the urban prefect Tatianus (450-c.452).
Obelisk of Theodosius Theodosius Dikilitaşı
Solid granite obelisk of Pharaoh Thutmose III (1479–1425 BC) re-erected in what was the central spina of the Hippodrome by Theodosius in the 4th c.
Walled Obelisk Örme Dikilitaş
Weathered medieval obelisk made of stone masonry. Repaired by Constantine VII in the 10th c., it was stripped of its adornments by the Fourth Crusade.
Arch of Theodosius Theodosius Zafer Takı Kalıntıları
Triple triumphal arch originally featuring statues of Arcadius and Honorius on either side, with Theodosius in the center. Only the base of the main arch remains.
Column of Arcadius Arkadyos Sütunu
Column commemorating Arcadius's triumph over the Goths in 400. Similar to the Column of Theodosius and that of Trajan and Marcus Aurelius in Rome. Toppled in 1715 for safety reasons.
Column of Constantine Çemberlitaş Sütunu
Column commemorating the declaration of Nova Roma as the new imperial capital in 330. Center of the non-extant Forum of Constantine.
Fort of Galata Yeraltı Camii
Tower from where the chain spanning the Golden Horn was sprung during sieges. First attested in 717, its remnant foundations are now an underground mosque.
Serpent Column Yılanlı Sütun
Ancient Greek bronze sacrificial tripod from Delphi (479 BC) relocated to the central spina of the Hippodrome by Constantine in 324.
'Tower of Eirene'
Square tower thought to be from the Middle-Byzantine era. Original name and function unknown.
Round 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.
Milion Milyon Taşı
Tetrapylon denoting the starting point for measuring distances to other cities of the empire.
Myrelaion Rotunda Mirelion Çarşısı
Second only to Rome's Pantheon in size, this mysterious rotunda served as a palace, cistern and monastery. Its foundations are now a subterranean bazaar.
Column of Justinian
Massive brick column covered in bronze, with Justinian on horseback atop it. Nearly as tall as the Hagia Sophia, it was knocked down soon after the Ottoman conquest for 'political' reasons.
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.
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.
Pege Gate Silivrikapı
Named after a 'life-giving' spring and monastery beyond it, the gate where forces of the Empire of Nicaea under Alexios Strategopoulos entered and retook the city from the Latins in 1261.
Xylokerkos Gate Belgrad Kapı
Named for the wooden circus (amphitheatre) it used to lead to, it became 'Closed Gate' to the Ottomans, as it had been walled up first against the Crusaders and again in 1453.
Gate of Charisius Edirnekapı
'Edirne (Adrianople) Gate', second only to the Porta Aurea in importance. Where Mehmet II made his triumphal entrance into the city.
Gate of Rhesios Yeni Mevlevihane Kapı
Well-restored gate whose towers feature inscriptions celebrating their swift construction: 'Scarcely could Pallas (Athena) herself have built so strong a citadel in such a short time'.
Gate of Saint Romanus Topkapı
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.
Porta Aurea Altınkapı
The main ceremonial entrance into the capital, used for triumphal processions to the Augustaion. Progressively walled up as the city's fortunes declined, it still cuts an imposing figure.
'Porta Putea' Cibali Kapısı
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.
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.
Basilica Cistern Yerebatan Sarnıcı
The largest of several hundred Constantinopolitan cisterns. Built by Justinian in the 6th c. beneath the site of the 3rd-4th c. Stoa Basilica.
Cistern of Philoxenos Binbirdirek Sarnıcı
The second largest cistern of the city, sporting 224 marble columns. Built under a palace in the 4th c., destroyed by fire in 475, it was restored by —you guessed it— Justinian.
Cistern of Theodosius Şerefiye Sarnıcı
Built by Theodosius II between 428 and 443 to store water from the Valens Aqueduct. Its 32 9m-high columns now support an underground modern art space.