Toprak Mansion, built by Turkish entrepreneur Halis Toprak, is in one of the most desirable areas of North London and occupies a good amount of space there. The house has about 28,000 square feet of space, not including the staff and guest apartments. That includes an 80-foot-long grand salon, a dining room that seats 40 and four kitchens, including one with a walk-in cold storage area. And what mansion would be complete without the glass elevator and Turkish bath? Trevor Abrahmsohn of Glentree Estates is handling the sale.