Best of Istanbul: 1 or 2 Day Private Tour

Day 1: Hagia Sophia, Blue Mosque, Hipporome, Topkapi Palace, and the Grand Bazaar
Explore the highlights of Istanbul on this private full-day walking tour that covers the major attractions, such as the Hagia Sophia Museum, the iconic Blue Mosque, the bustling maze of the Grand Bazaar, and the obelisk of the Hippodrome of Constantinople.
The 8-hour excursion starts with a pickup from your Istanbul hotel and a walk through the lively streets of Turkey’s largest city to visit the dramatic former basilica of the Hagia Sophia, a great architectural beauty and an important monument during the Byzantine and Ottoman Empires. For many centuries, this was the largest church in the world, and it still boasts the 4th largest dome after St. Paul's in London, St. Peter's in Rome, and the Duomo in Florence.
Move on to the Blue Mosque, more officially known as the "Sultanahmet" Mosque. The mosque’s striking blue tiles give it its more common name and make it one of Istanbul’s most iconic attractions. Located close to Topkapi Palace, Sultanahmet Mosque was considered the Supreme Imperial Mosque in Istanbul.
Continue to Topkapi Palace, a relic of the glory days of the great Ottoman Empire. The former palace boasted a population of about 4,000 people at its peak and was home to 25 sultans over a period of 400 years. Located on a promontory overlooking the Golden Horn, it sits in tranquil gardens that provide shade from the blazing heat of the summer. 
You will also visit the Hippodrome, the former circus built in 203 AD by the Roman Emperor Septimus Severus. Three monuments from the original building remain, including the Egyptian Obelisk, the Serpentine Column, and the Constantine Column. You will also pause to look at the German Fountain of Wilhelm II, made from 8 marble columns.
Day 2: Spice Bazaar, Bosphorus cruise, Dolmabahce Palace, Istiklal Street, and Taksim
The spice bazaar is located in Fatih. It's known as the Egyptian Market because during the Ottoman period, Egyptian exports were sold there. The Bosphorus is a narrow, navigable strait between Europe and Asia that connects the Black Sea to the Marmara Sea. Rumeli and Anadolu Fortresses are located at the narrowest point of Bosphorus. There are also magnificent Ottoman palaces and mosques along the Bosphorus. Keep an eye out for them.
Built in the 19th century, Dolmabahce Palace was the administrative center of the Ottoman Empire and housed some of the last Ottoman Sultans. The palace site was created by filling in the small bay on the Bosphorus. This gave rise to its name — in Turkish, Dolma means 'filled' or 'stuffed,' and bahce means 'garden'.
Istiklal Street is brimming with life. There, you'll find a plethora of shops, restaurants, and bars. From there, it is then a 2-kilometer walk down to the Tunel Galata Tower area.