Cascais
A visit at the open market on Wednesday or Saturday and then a lunch at the Mercado da Vila
https://www.cascais.pt/sub-area/feiras-e-mercadosAfternoon tea at the Albatroz Hotel
https://www.thealbatrozcollection.com/albatrozhotel/cascais-afternoon-teaA walk on the Paredão and a moment at the beach Praia do Tamariz
https://www.cascais.pt/galeria-de-imagens/paredaoSeafood at Surpresa (Estoril)
https://goo.gl/maps/nTTByj4ibdVvaiAy7Go by train from Cascais to Lisbon and enjoy the seaview
And for a second day:
Casa da Guia – Cascais: https://casadaguiacascais.pt
Restaurante Furnas do Guincho: https://www.furnasdoguincho.pt/Other ideas: https://www.timeout.com/cascais
In Lisbon
A visit to the Oceanário de Lisboa
https://www.oceanario.pt/A walk in the Jardim da Estrela
https://www.jf-estrela.pt/comunidade/locais-a-visitar/1-jardim-da-estrela
In Sintra
A visit to the Quinta da Regaleira
https://www.regaleira.pt
Further away
Praia da Saude (Costa da Caparica)