Baron Empain's own residence adopted a unique south Asian architectural style. Alexander Marcel, a French architect and a member of the prestigious French Institute, was commissioned by Empain to build him a Hindu style palace. Modelled on Angkor Wat in Cambodia and the Hindu temples of Orissa, the palace was erected between 1907 and 1910. It still stands today, remaining one of the finest examples of early creative use of concrete, of which it was entirely built. The neighborhood had some of the wealthiest Egyptian residences; on the left facing Avenue Baron was the Arabesque palace of Boghos and Marie Nubar Pasha, now a military headquarters. The Pasha assisted Baron Empain in purchasing the 6,000 acres (24 km²) of open desert, at one pound each, on which he built Heliopolis. Diagonally opposite stands the former residence of Sultan Hussein Kamel, who reigned over Egypt between 1914 and 1917. Today, it is a presidential guest house.