Cais do Tojo is excepcional. The apartment is new and everything is thoughtfully and lovingly taken care of, Teresa is an exquisite host.
The location is safe and quite but convenient, at strolling distance to Chiado, Bairro Alto or Alfama. There is a taxi stand around the corner for longer distances and taxis in Lisbon are unexpensive.
The Cheese and Wine store on the ground floor is also a really nice convenience for those nights you prefer to stay at home and feel like a local.
We had a great time in Lisbon and this apartment was certainly one of the high points.