Such a good find!
The apartment is in the Principe Real area of Lisbon which was a great neighbourhood to stay in with a lot of nice restaurants and pastry shops nearby. There is a little supermarket with everything you need just down the road from the entrance to the apartment.
There is a nice little park (Jardim de Principe Real) nearby and an even nicer park / lookout point just a bit further down the road (Miradouro de Sao Pedro), about 10 mins walk away from the apartment. We visited this every evening either to watch the sunset or after dinner on our way home. The park has great views from the hilltop over Lisbon and great stalls selling food and drinks.
Communication from Nuno beforehand was excellent with really good instructions on finding the apartment. His friend who greeted us at the apartment was also super friendly and provided us with a map and pointed out a few local areas of interest and useful information. The apartment itself is very nicely decorated and has everything you need (including a washing machine etc). The shower and bed are also great - all in all I would say it's more like a nice hotel suite with lots of useful amenities than just an apartment. I would definitely stay here again if visiting Lisbon.