That place calls Lagoa de Obidos but in the summer we can't kite there(june/july/August).
But there are other places.Like Viana do Castelo-Cabedelo, Esposende, Peniche, Nova Vaga Beach in Caparica(Kite beach south of Lisbon), Lagoa de Albufeira, Peninsula of Tróia(I have a center here
http://www.troianaishcenter.eu), Vila Nova de Mil Fontes, Faro, Alvor, etc.
Most of the people in the centers speak English.
And the wind in August is normaly North and the force vary from place to place.
You are welcome.