Busting out a 2-day trip to Rome sounds crazy, but it is definitely doable. We spent our first day at the Vatican City and our second day for Imperial Rome. There was alot of walking on cobble stone streets for sure, so make sure you grab a pair of good shoes. My favorite part was definitely visiting the Vatican Museum and seeing Michelangelo's Sistine Chapel ceiling with my very own eyes.
Day 1: Vatican City
We started our day out with the Vatican Museum, knowing that it is known to have super long waiting lines - and we went wrong. We got there around 8 AM (an hour before Vatican Museum opens) and we were still in line for around 3 hours. So definitely recommend buying tickets in advance and lining up at least 1.5-2 hours before it opens at 9 AM. If you are not the patient type, there are always private tour guides along the waiting line who try to sell you to skip the line (with a much higher entrance fee in exchange of course).
Vatican Museum is quite a big place to walk around - you can spend the whole day there if you want. But do keep in mind that if you do want to see the Sistine Chapel, sadly there's a separate line for you to wait again. On the bright side, it is free to public. Lots of waiting to do but it is definitely worth the sight.
After spending the first half of our day at Vatican Museum and Sistine Chapel, we spent the rest of our time roaming around streets and hitting some must-see things like the Trevi Fountain - can't miss having a Lizzie McGuire moment of course!
Stop by Giolitti & Frigidarium for some quality gelato if you get the chance!
Day 2: Imperial Rome
We actually went to the Colosseum towards the end of the day around sunset time, although the lighting was perfect - we got there right when the entrance closed so could not go inside unfortunately. So if I visit again, I would definitely go visit the Colosseum and forum first thing in the day!
Walking along the forum, we found ourselves at Capitoline Hill and climbed up top to get a great night view of the city.