Our stay in Barrio Alto was great. The apartment was perfect and had all the necessary items when traveling with children. Very easy to find all you need within walking distance. Principe Real park is a quiet little gem that comes as a perfect place for a pit stop before heading back to the apartment. Apartment is located in a very quiet monastery. You do hear loud conversations from the street next to the apartment, but this would be the case with most probably many apartments in Lisbon. Luckily the streets around the apartment are not very busy. We slept well and our kids too :)