The two of us stayed at Kat's place for 10 days, a lengthy and at times exhausting trip. Her apartment provided a wonderful respite from our busy days in the city. It is located in a quiet part of Montmartre (when we walked over the hill to the west side of Sacre Coeur -- very busy and touristy -- we were shocked that where we were staying was considered the same area). The Chateau Rouge metro station on the 4 line is a short walk which made is so easy to get in and out of the central parts of the city. Highly recommend for a relaxing stay in Paris!