I am quite confused about getting tickets to these two places. I've purchased tickets to the Vatican Museums and Sistine Chapel online through the Official website, then I read that they also offer a "combine" ticket of these two places and St. Peter's Basilica. Some website say that it's free to enter St. Peter's Basilica so why is there this "combine" ticket? Then "The Rome Toolkit" website say that admission fee is required to climb the Dome and to St. Peter's Treasury. Where do I buy tickets to these two places? Will we have to stand in a long queue to buy those tickets or can we buy them online?