It's up four flights of stairs on a spiral staircase. Wonderful spacious apartment with everything you need. Axelle responded quickly to our emails while there. It is on a busy, lively street with restaurants and bars where the party does sometimes spill out into the street and can go long into the night. It was hot, so we had our windows open and the noise is pretty much just a background hum except for the occasional opera singer or outbreak of Bohemian Rhapsody. But that is part of the attraction of the location.
The location was killer. Fifteen minute walk to the Seine and Notre Dame. Great boulangerie down the street. Two grocery markets open late. Creperie two doors down (ask him to surprise you). Every kind a restaurant/bar/gift shop you could possibly want is within a very short walk. The neighborhood market is on Saturdays. Minutes to the Pantheon. To get out of the neighborhood use the Cardinal Lemoine station on line 10 instead of Place Monge. It's two minutes more walking but connects to everything.