If you've visited the Vatican Museums and Sistine Chapel in Rome, then you probably did so with thousands of other people - or, to be more precise, tens of thousands. The attraction is a magnet for a mindbogglingly 25,000 people a day. The hours of waiting in the inconceivably long line that stretches around the huge block that's home to the Vatican and St Peter's Basilica, all the way to the square itself, is a major deterrence for many. It was for us on our first trip to Rome ten years ago. And even if you're smart enough to book tickets in advance, or desperate enough to join a tour group, once inside the experience can be tremendously disappointing. You're swept up in a sea of sweaty people and the feeling is akin to drowning. There's little room to move to stop to appreciate something that might catch your eye. You can't hear yourself think to even begin to reflect upon the exquisite art for the constant hum of thousands of voices and the interminable irritating lectures shouted out by guides to their groups in an attempt to be heard above the drone. The hundreds of little flags in the air waved about by guides so they don't lose any sheep from the flock obstructs your vision. Movement through the galleries is at a snail's pace simply because there is nowhere to move so everyone shuffles slowly along. Descending the stairs was a suffocating experience, and not one for claustrophobics. Once inside the Sistine Chapel, where entry is measured and numbers restricted, we were whisked through so swiftly (so the other 24,998 people could have their turn!) that there was little time to enjoy what must be at one and the same time the world's most sublime religious monument and one of the most breathtakingly beautiful art galleries on the planet. My memory of the chapel as a result was hazy, so when Viator, whom we occasionally write for (see our Top things to do in Dubai and our Dubai Guide: Top 10 off the beaten path experiences), invited us to join a private after hours tour we jumped at the chance. The experience was the complete opposite of that first visit four years ago. The corridors were so quiet you could hear a pin drop on the marble floor. Our expert guide - an art historian with a PhD who spent 3 years in the Vatican libraries researching her thesis! - was able to take her time pointing out important works, and she explained them with an infectious enthusiasm and such passion that she had tears in her eyes at times. We got to dawdle through the galleries and stop wherever we wanted to admire the work. And as for our visit to the Sistine Chapel itself, we had so much time to take in the sublime space that each painting is so firmly imprinted in my mind that if I was an artist I could sketch out the entire interior for you. A private tour is the only way to go. And if you don't believe me, do it both ways and then let me know what you think. I'll let you know when our post about the experience is up on the Viator blog.