The purchase of a Euro 100 million Istanbul mansion (yali) - the fourth most expensive property in the world - by a Qatari monarch has set tongues wagging. The Bosphorus yali is a prime example of the luxurious real estate found in Turkey's largest, city. The purchase also solidifies Istanbul´s reputation as the firm favourite of Middle Eastern buyers, who are flocking to the city in search of private residences and lucrative buy-to-let properties.