Absolutely recommended
One of the best surprises on our holiday to Portugal was the restaurant "O Arco" in Santiago do Cacem. We travelled the Algarve to Lisbon and we stopped in this town to eat. I asked a local and he very kindly recommended O Arco. He pointed out the place and warned us about the portion size, which was plentiful. Although the location of "O Arco" with a BP petrol station is not very glamorous, what matters is the good food at a good price. In the picture you can see what we ordered for four people (Anna, the friendly waitress recommended that we order nothing else): baked cod (one of the best cod I've ever eaten in my life, and this fish is one of my favorite), rice with roast duck (according to my wife, one of the best dishes in years) and pork tenderloin with cream (with fried egg on top, if there wasn't enough).