The Haghia Sophia is one of the most famous structures in the world, and if any one building can be said to give a real sense of Istanbul’s history, then this is it. Built nearly 1,500 years ago and completed in 537 under Emperor Justinian, this towering, beautiful edifice has seen the changing fortunes of the city from earthquakes, to torching by rebels, to the plundering and desecration of marauding Crusaders. Once the largest enclosed space in the world, it was built as a cathedral by the Byzantines to illustrate the strength and wealth of the empire, and it still stands today as a fantastic testament to their accomplishments. Later Ottoman architects, including the most famous, Mimar Sinan, spent most of their careers trying to emulate the technology and proportions of this enormous building. Nowadays, while standing and gazing upwards into the massive dome with daylight piercing through the small windows, visitors, catching glimpses of the sparkling mosaics, can easily understand why the Haghia Sophia remains one of the most inspiring buildings in the world.