Great location for a trip with the girls, your family or what ever! Both Estoril and Cascais are beautiful towns with everything you need. Apt is close to the beach, board walk with running and biking tracks and an outdoor gym overlooking the ocean, paddle, surfing, taking a boot trip, riding bikes along the coast line etc. Also good if you want to travel around to the different palaces, the other surf beaches or take the train or uber in to Lissabon.
Loved the terrass with a clips of the ocean and beautiful houses around as well. Apartment was very well designed and bathrooms well equipped with Rituals soap and schampoo etc and fluffy towels ;) Beds and linnen were also very nice. I was on the second floor and no elevator so not for everyone, but well worth taking the stairs! I could definitely live in this apartment full time ;)!