Stare at Hagia Sophia in Wonder
Hagia Sophia is the crown jewel of Istanbul. It was first built around 532 - 537 AD by the Byzantine Empire as a principal church for its capital city before it was taken over by the Ottoman Empire and converted into a mosque in 1453. Once the Ottoman Empire collapsed, the Turkish government decided to convert the mosque into a museum and began restoration work for the most part until 2020 when it was finally converted into a mosque again with much fanfare.
Back when it was a museum, you have to pay around 100 TRY to enter but now that is converted into a mosque for regular service, you are now free to enter as you please which is a welcome change despite all the fiery worldwide discussions over its conversion. Once you are inside, you will be surrounded by a breathtakingly gigantic domed hallway all painted yellow and 8 Arabic calligraphic roundels, huge circular wooden panels that bears the names of Allah, Mohammed, and his grandsons; Hasan & Hussein, and four caliphates.