The Basilica Cistern Museum, one of Istanbul's countless historical buildings, was reopened to visitors with the completion of the restoration process that started in 2017. In addition to the earthquake strengthening works, the lighting was also overhauled in the museum.

The Basilica Cistern, known as Yerebatan Sarnıcı or Sunken Cistern in Turkish, is one of the most popular historical destinations in Istanbul and within walking distance of other Byzantine and Ottoman-era landmarks like the Hagia Sophia Grand Mosque and Sultanahmet, or the Blue Mosque.

It was built by Byzantine Emperor Justinian I in 542 and known as the Basilica Cistern because there used to be a basilica at the same location. In Turkish, it is known as the Yerebatan Sarayı or "Subterranean Palace" due to the marble columns rising out of the water.

The cistern is an underground chamber approximately 138 meters (452.76 feet) by 65 meters. It covers an area of 9,800 square meters (105,486 square feet) and is capable of holding almost 80,000 cubic meters of water. Meeting the water needs of the Byzantine palaces and other residents in the area, it was used for a while after the conquest of Istanbul by Ottoman Sultan Mehmed II in 1453.

The Basilica Cistern impresses visitors with its 336 columns, each 9 meters tall, and two Medusa heads. The columns are mostly cylindrical and made out of a single block. The two Medusa heads, two great examples of Roman era architecture, garners a lot of attention. Both work as the bases for two of the 336 columns located on the northwest side of the cistern. They are thought to have been brought to be used as supports for the columns at the time of construction of the cistern.

. As part of the restoration, launched in 2017, the ties fixing the columns to each other were renewed to prepare the construction for a possible earthquake. The entrance hall of the cistern was also redesigned while the lighting was renovated. The cistern now hosts visitors with an exhibition themed "light."

The Basilica Cistern Museum can be visited between 9 a.m. and 5 p.m.