Dolmabahçe Palace

This palace was the gubernatorial heart of the entire Ottoman Empire in the late 1800s; as a result, it’s, unsurprisingly, the most opulent building in Istanbul, occupying an area of 45,000sqm (484,375sqft) with 285 rooms. Today, it houses two museums, meaning it should be your first port of call if you’re interested in the history of Istanbul.