The hippodrome of Consantinople used to be located
in what is now the Sultanahmet neighborhood of Instanbul.
Chariot races were held there (as I believe is the case
with all hippodromes since the term refers to
the road of horses; dromos is Greek for way or road
and hippos is Greek for horse).
Although the hippodrome is known as the hippodrome
of Constantinople, it was actually built by
Emperor Septimus Severus in CE 203 which was
during the Byzantium empire here. It was so large that
something like 100,000 people could attend the events.
During the Ottoman Empire, it was left in ruins.
Crusaders sacked Constantinople and the hippodrome
was pillaged of many sculptures. The Ottoman empire
was not interested in the chariot and horse races
so the stones of the hippodrome were used as
building materials for the construction of Istanbul
which was made the capital of the Ottoman empire.
The location was not bulit over and thus,
there was the opportunity to create a large,
beautiful park with a fountain in its center. Several
monuments from the hippodrome still exist here though.
These include, Serpent Column, Obelisk of Thutmose III,
and the Walled Obelisk. The fountain was built in
1900 by the German government to celebrate
the visit of German Emperor Wilheim II. It is built with
an octogonal shape in a neo-Byzantine style.