While the Princes Islands are just a short trip from Istanbul, visitors who step onto the ferry leave behind more than just a big city - they depart the trappings of modern life and enter a long-forgotten world of horse-drawn carriages and wistful Victorian mansions. Once a place of exile for Byzantine and Ottoman royalty, today the islands are enjoyed by day trippers who explore their beaches and pine forests. Although it's rare to find real estate for sale on the Princes Islands, a 140 year-old mansion for sale offers not only the chance to experience life as part of this intriguing archipelago, but an opportunity to invest in a successful rental business.