While Sintra's palaces are magical for culture lovers, serious hikers and water enthusiasts should consider Arrábida Natural Park — Better trails, minimal crowds, and some of the clearest Mediterranean waters you'll find north of the Greek islands. The Portinho da Arrábida to Praia da Figueirinha coastal trail delivers 3km of limestone cliff hiking with visibility often hitting 20+ meters on calm days, perfect for snorkeling and underwater photography.

Take the train from Oriente station to Setúbal (€3.45, 1 hour), then local bus 561 to the park entrance at Portinho da Arrábida (€2.10, 25 mins, runs hourly). The trail starts right from the beach parking area — Follow the white and yellow markers along the cliff edge. Moderate difficulty with some scrambling over rock sections, allow 2-3 hours with photo stops and swimming breaks.

The marine life here is exceptional for temperate waters. I regularly spot octopus, cuttlefish, and massive schools of bream in the rocky shallows. Bring a quality mask and snorkel — The underwater limestone formations create these incredible swim-through channels that rival tropical dive sites. Water temperature peaks around 22°C in late summer, but a 3mm wetsuit extends the season through October.

Pack everything you need because there are zero facilities on the remote sections. I always bring 2+ liters of water, energy bars, and a dry bag for electronics. The cliff exposure means weather can change quickly — Check marine forecasts on Windguru before heading out. The sunrise hikes are spectacular but start early; parking fills up fast on weekends even at this hidden gem.