David is a wonderful host with lots of recommendations to make the most of your stay in Lisbon. He even made a dinner reservation for us at his favorite seafood place in Cascais, a beautiful town we wouldn't have even gone to without his urging. The flat is in a very good location...walkable to the riverfront, Chiado and Bairro Alto districts. We took the train to Cascais and Sintra, both very worth the trip. The flat had plenty of space for our family of 4. As others have said, there are a LOT of steps...both up to the flat and the surrounding neighborhood. We definitely got our exercise during our time here:)