Hagia Sophia (Aya Sofya):

Established in 536 AD by the great Justinian, the emperor of Byzantine Empire. It was the largest cathedral at that time and the center of the world and a proof of Byzantine empire’s advanced technology in architecture. After Ottoman empire armies conquered the city, Hagia Sophia cathedral was turned into a mosque and kept serving for more than four hundred year until the first world war when the turkish Republic was formed and the hagia Sophia became a museum to tell the entire story of 1500 years.
When you enter the Hagia Sophia you will be amazed by it design and interior decoration, it is more than a masterpiece

The Hagia Sophia museum is located at SultanAhmet Square you can reach it through T1 Tramway line.

The Basilica Cistern (Yerebatan Sarniçi):

The-Basilica-Cistern

One of the world’s most amazing and breathtaking places. The cistern looks like a huge palace hall with its 336 columns that line up in 12 raws and the construction works started during the rule of Byzantine emperor the great Constantine but was finished in the 6th century during the rule of emperor Justinian.
This Cistern was the main source of water for Istanbul city for many centuries because of its ability to hold up to 2.8 million cubic feet of water.
One of the interesting things about this cistern is the two columns that has Medusa head on them to protect the cistern as it was believed.
The trip to Basilica Cistern is very mysterious and historical, you should definitely visit it, it is located in yerebatan caddesi in SultanAhmet region.

Istanbul Archaeology Museum:

This museum is Turkey’s most important museum because it gathers artifacts and items from the Middle East, Asia and Europe.
The museum consists of three museums, the main Archaeological Museum, the ancient Orient Museum, and the Tiled Kiosk Museum. Those three museums combined, contain more than one million historical items from civilizations from all over the world, in addition to the Sarcophagus of the great Alexander.
You can see Istanbul through the ages at the Archaeological Museum, do not miss it.
It is located right next to the Topkapı Palace.

The Grand Bazaar:

If you do not know, the Grand Bazaar is the oldest and first covered market or mall in the world. This market is where everyone gathered to do shopping or see the traditional Turkish products.
The Grand Bazaar has eleven entrances and contains approximately four thousand shops that offer hundreds of types of products such as souvenirs, traditional Turkish desserts, jewelry, antiques, clothes, carpets and many other products.
Even if you are not a fan of shopping and do not want to spend a lot of money, you can walk between the shops, take some pictures and then finish your trip eating Et Doner Sandwich at one of the restaurants there.
You can reach the Grand Bazaar through T1 Tramway line, it welcomes visitors from 9 am until 8 pm everyday but Sundays.

Istiklal Street:

Istiklal Street is different from the old historical sights in Istanbul, with the french designed buildings on both sides and many cafes and restaurants under them Istiklal Street considered one of the most active shopping streets in Istanbul.
There is no specific atmosphere or feeling that you feel when walking down this street but the red old train that transfer people from the beginning of the street to the end of it will take you back to the old simple days.
At the end of the street you will find the famous Galata Tower where you can go to the top of it to see the wonderful view of Istanbul.