The Rockefeller Center Christmas tree in New York City.AP Photo/Julia Demaree NikhinsonLandmarks are decked with festive decorations this Christmas season.Among these, New York's Rockefeller tree and London's streets are iconic holiday attractions.But holiday markets in Poland and Spain also make for festive getaways.Come Christmastime, some of the most famous monuments, malls, and markets around the world get decked out in their festive best.There's the Rockefeller Christmas tree in New York City, which is adorned with 50,000 LED lights and crowned by a 900-pound Swarovski star.