Sintra is probably the most popular day trip destination from Lisbon. My sister and Tiago were busy, so I joined a group of Australian round-the-world-trippers on an organised tour, run by "We hate tourism Tours". And that guy really lived up to expectations! Knew little about dates or dynasties, but everything about crazy Portuguese driving and where to best climb the walls into Quinta da Regaleira, one of Sintra's UNESCO-listed palaces. The castle is surrounded by an enchanted labyrinth of mythic grottoes, esoteric statues, ponds and wells, like the "Initiation Well", something like an upside down tower, opening out into a narrow underground tunnel, supposedly symbolising the journey from hell to paradise... Whatever the real history, in his youth our tour guide must have had a wonderful time here! Apparently the whole Regaleira estate wasn't touristically developed until some 15 years ago. Back then, there were no fences, no rules, no controls - and hallucinating youngsters from Lisbon used to err around the Quinta's magic forest from Friday night till Monday morning. Our guide kept repeating "Don't eat the plants. I know. There're deceptive. It's no good..."
We had lunch at Cabo da Roca, the westernmost point of mainland Europe. The cape makes a nice pick nick spot, but apart from that, as you can see, there is not much to see. Been there. Done that.