I had two nights at Maria's place which is very centrally located in the downtown Chiado district. Maria was very welcoming and could not have been more helpful. Her place was very comfortable and the area was quiet, so absolutely no problem sleeping. The area around has a nice local neighborhood feel and there are two great simple neighborhood restaurants very close by - one is called the Faca e Garfo (Knife and Fork). Absolutely no hesitation in recommending Maria's place!