The Walled Obelisk.

Beyazit Tower, built in 1856.

Constantine's Column. This column was brought from the Temple of Apollo in Rome and erected in Istanbul. It is believed that it was originally topped by a statue of Apollo greeting the dawn. The column was made of eight porphyry drums which were wreathed with laurel.

The statue of Constantine which adorned the column's top was later replaced with a statue of Theodosius, which was later dislodged by a bolt of lightning in 1081. The column was restored by Alexius Comnenos I and a gilded cross and inscription on the capital replaced the statue. A severe fire damaged the column during the reign of Mustafa II, who subsequently had a layer of stone added to the base and iron hoops affixed around the body. The column derives its name, Cemberlitas, 'Hooped Column' from these iron rings.
The Serpentine Column.

The Walled Obelisk

At the rear part of Sultanahmet Square is a column repaired by Constantine VII. The obelisk, constructed of ashlar blocks, is 32 m. in height, and is reputed to have been decorated with bronze plates depicting the victories of Constantine and his grandfather Basil I (867-886), and crowned with a sphere. Unfortunately, however, these bronze artifacts are said to have been melted down by the Latins for use in the mint.

The Serpentine Column

This column was brought to Istanbul in 330 A.D. by Constantine the Great from the temple of Apollo at Delphi. It was originally presented to the temple of Apollo by the 31 Greek cities as a token of gratitude for their defeat of the Persians in the maritime battle of Platea in 479 B.C.

A golden vase was set on top of the column, which was in the form of three interwined snakes. It was 8m high, including the triple snake heads, which appeared towards the top of the column at a height of 6.5 m. Records show that these snake heads were in place at the beginning of the 16th century, after which they were broken off.