Our day today was spent walking towards Notre Dame and wandering around the Musee du Louvre. The Notre Dame is beautiful from the outside, and would have loved to have visited the inside… but the queues were a bit insane when we visited.
We will have to visit the inside of the Notre Dame next time we visit Paris. Afterwards we headed towards the Louvre, and although the queue seemed long it moved very quickly. After clearing the security screening there was a lot of areas for purchasing tickets (including from vending machines) which was fantastic. Within minutes of entering the Louvre we were in the exhibits wandering around, which was a lot faster than I anticipated.
Would highly recommend visiting the Louvre, but if you do try to go on a evening opening (e.g. the Friday) and go earlier in the day. Highly recommended to make a full day of it, as the museum is absolutely massive and the exhibits other than the Mona Lisa are very beautiful and worth visiting if you have the time.