“Kingdom of Heaven” writer William Monahan will turn his attention from the 12th century Crusades to the 13th century Far East explorations of Marco Polo. Monahan has been set by Warner Bros. to write “Marco Polo,” a historical epic based on Polo’s autobiography “Travels.” A deal is being negotiated for Matt Damon to play the explorer. In his adventures, Polo ventured farther into Asia than any Westerner before him. His journey took 24 years, during which Polo became a confidante of Kublai Khan and witness to many technological advances of China and Mongolia. No date has been set for when the film will start production.