What are the best day trips from Lisbon?

Sintra over everything if you only have one day to give. The CP train leaves Rossio every 20 minutes (€2.30 each way on a Viva Viagem card, 40 minutes), and by 9:30 you're standing in fog-damp forest listening to parakeets argue in the canopy above Quinta da Regaleira. That's the one for couples — the initiatic well spirals nine stories underground, the grottoes drip, and you'll have the place mostly to yourselves if you're there when gates open at 9. Pena Palace gets the postcard shots but the crowd hits hard by 11am and the interior is, to be fair, smaller than the exterior promises. Split the day: Regaleira in the morning, lunch at Tascantiga on Rua Volta do Duche (the braised black pork cheeks, around €14), then walk to Monserrate Palace in the afternoon — far fewer visitors, gardens thick with jasmine and damp stone. Last train back runs around 9pm. Worth noting: the cobblestones in Sintra's old center are brutal in heels or thin soles.

Cascais is the low-effort day out. Train from Cais do Sodré, same Viva Viagem card, 33 minutes along the Tagus then the coast — you watch the water shift from brown river to green Atlantic through the window. The town itself is pleasant but not worth a full day unless you rent bikes and ride west to Guincho beach, where the wind comes off the open ocean hard enough that you taste salt on your lips from the promenade. For the afternoon, double back to Casa da Guia for wine overlooking the cliffs. Arrábida, on the other hand, is the best beach day within reach — Praia de Galapinhos has cold, clear water backed by limestone hills covered in low scrub — but there's no useful public transport. You need a car. Rent from the airport area the night before (expect €35–45 per day in May), drive the N379 along the ridge, stop wherever the pullouts look good. Bring a cooler and towels. The beach bars are unreliable.

Óbidos works well as the shared-interest compromise. The history half of the couple gets a walled medieval town where you can walk the ramparts — stone warm underfoot in the afternoon sun, views over terracotta rooftops and vineyard rows. The food half gets ginjinha, the sour cherry liqueur they sell in chocolate cups from stalls along the main street. One euro a shot. You'll have three. The Rede Expressos bus from Campo Grande takes about an hour (around €8 each way, runs five or six times daily), or you drive in 50 minutes. The town is small — walkable in two hours flat — so pair it with a stop at Buddha Eden on the way back, a wine estate with a free sculpture garden and €10 tastings. Honest warning: Óbidos is a single main street, and by early afternoon in summer it packs tight with tour groups from Lisbon. Go early or go midweek.

Évora is the full-day commitment. It sits 130 km east and the Intercidades train from Oriente takes about 1h30 (€12–16 each way, book on cp.pt a few days ahead). The Chapel of Bones is exactly as unsettling as it sounds — walls lined floor to ceiling with human skulls and femurs, cool and dim inside, the air dry and faintly dusty. The Roman Temple of Diana stands a five-minute walk away, columns still upright after two thousand years, warm yellow limestone catching the late-morning light. For lunch, Botequim da Mouraria on Rua da Mouraria is a counter with maybe eight stools — the owner serves what he cooked that day, usually slow-braised pork or lamb, and you eat elbow to elbow with locals. About €15 for a full meal with wine. Mind you, return trains thin out after 8pm, so check the schedule before you settle into a second bottle of Alentejo red.