Hagia Sophia ( ; from the Greek: Αγία Σοφία , ] , "Holy Wisdom"; Latin: "Sancta Sophia" or "Sancta Sapientia"; Turkish: "Ayasofya" ) was a Greek Orthodox Christian patriarchal basilica (church), later an imperial mosque, and is now a museum (Ayasofya Müzesi) in Istanbul, Turkey.
 The Roman Empire's first Christian Cathedral, from the date of its construction in 537 AD, and until 1453, it served as an Eastern Orthodox cathedral and seat of the Patriarch of Constantinople, except between 1204 and 1261, when it was converted by the Fourth Crusaders to a Roman Catholic cathedral under the Latin Empire.
 The building was later converted into an Ottoman mosque from 29 May 1453 until 1931.
 It was then secularized and opened as a museum on 1 February 1935.
 Famous in particular for its massive dome, it is considered the epitome of Byzantine architecture and is said to have "changed the history of architecture".
 It remained the world's largest cathedral for nearly a thousand years, until Seville Cathedral was completed in 1520.
Nicholaus Kanabus was elected Emperor of the Byzantine Empire during the 4th Crusade on 25 or 27 January 1204 by an assembly of the Byzantine Senate, priests, and the mob of Constantinople in direct opposition to co-emperors Isaac II and Alexios IV.
 Nicholaus was a young noble (probably a relative of Angelid emperors) who was chosen after three days of sorting through several unwilling candidates and refused to assume the lofty position.
 Though popularly chosen, he never accepted imperial power, and took Sanctuary in the bowels of Hagia Sophia.
 Alexios V "Mourtzouphlos", who had deposed Emperors Isaac II and Alexios IV, offered him a prominent position in his own administration, but Nicholaus adamantly rejected these terms.
 On February 8, after rebuffing an imperial summons, Emperor Nicholaus Kanabus was dragged out of the church, in which he had sought refuge, and strangled on the ornate marble steps of Hagia Sophia.
Hagia Sophia means either "Holy Wisdom" or "Saint Sophia" (Ἁγία Σοφία , Agia Sophia in Greek, Sancta Sophia in Latin, Ayasofya in Turkish).
 "The Holy Wisdom of God" is a name for the Second Person of the Trinity.
Piyer Loti Museum is a museum in İstanbul, Turkey.
 "Piyer Loti" refers to Pierre Loti (1850-1923) , the French novelist who spent a part of his life in İstanbul.
The Basilica Cistern (Turkish: "Yerebatan Sarnıcı – "Cistern Sinking Into Ground"" ), is the largest of several hundred ancient cisterns that lie beneath the city of Istanbul (formerly Constantinople), Turkey.
 The cistern, located 500 ft southwest of the Hagia Sophia on the historical peninsula of Sarayburnu, was built in the 6th century during the reign of Byzantine Emperor Justinian I.
The Theodosius Cistern (Greek: Κινστέρνα Θεοδοσίου , Turkish: Şerefiye Sarnıcı ) is one of many ancient cisterns of Constantinople that lie beneath the city of Istanbul, Turkey.
 The modern entrance is in Piyer Loti Caddesi, Fatih.
The Palace of Boukoleon (Greek: Βουκολέων ) or Bucoleon was one of the Byzantine palaces in Constantinople (present-day Istanbul in Turkey.)
 It was probably built by Theodosius II in the 5th century.
 The palace is located on the shore of the Sea of Marmara, to the south of the Hippodrome and east of the Little Hagia Sophia.
The Church of St. Polyeuctus (Greek: , "Hagios Polyeuktos") was an ancient Byzantine church in Constantinople (now Istanbul, Turkey) built by the noblewoman Anicia Juliana and dedicated to Saint Polyeuctus.
 Intended as an assertion of Juliana's own imperial lineage, it was a lavishly decorated building, and the largest church of the city before the construction of the Hagia Sophia.
 It introduced the large-scale use of Sassanid Persian decorative elements, and may have inaugurated the new architectural type of domed basilica, perfected in the later Hagia Sophia.
The Magnaura (Byzantine Greek: , possibly from Latin "Magna Aula", "Great Hall") was a large building in Constantinople.
 It is equated by scholars with the building that housed the Senate, and which was located east of the Augustaion, close to the Hagia Sophia and next to the "Chalke" gate of the Great Palace.
 A large gate, described by Procopius, probably made out of marble led into a peristyle courtyard which led to the Magnaura.
 The building, a basilica with three naves, was subsequently used as a throne room and a reception hall, and in ca. 855, the "Caesar" Bardas established in the palace a school ("ekpaideutērion").
 However, this was not the University of Constantinople, but rather a Philosophical school, because the University of Constantinople was created during the time of Theodosius II in 425 AD.
Theodorus Lector (Greek: Θεόδωρος Ἀναγνώστης , "Theodoros Anagnostes") was a lector, or reader, at the Hagia Sophia in Constantinople during the early sixth century.
 He wrote two works of history; one is a collection of sources which relates events beginning in 313, during Constantine's early reign, down to 439, in the reign Theodosius II.
 The other is Theodorus' own work, retelling events from the death of Theodosius II in 450 to the beginning of Justin I's reign in 518.
 The former work is important to scholars editing the authors quoted by Theodorus; the latter exists only in fragment and owes its importance more to the "scantiness of our information concerning the period it treats rather than its merits."

Question: Which of these has its entrance in Piyer Loti Caddesi, Hagia Sophia or Theodosius Cistern?
Answer: Theodosius Cistern