The apartment is in a delightful neighbourhood on Monte Estoril. It was cosy, super clean, and has a good amount of kitchen equipment to cook if you desire. One thing to note - it is a bit steep from the beach/metro to get to the place, but no problem if you are mobile.
Tiago is a considerate host and gave me very good recommendations for local places to check when I asked him. I can only recommend his place highly for a relaxing stay near Cascais.