The Linha de Sintra runs from Rossio station in central Lisbon northwest to Sintra in 40 minutes. Trains run every 20 minutes; no advance booking required. The line climbs gradually through the Lisbon suburbs and into the lower edge of the Serra de Sintra.
A direct word about Sintra's topography: The famous palaces - Pena, the Moorish Castle, and Monserrate - sit on the forested mountain ridges above the town and all require significant uphill effort to reach, either on foot (steep) or by the Scotturb tourist buses that serve them. This itinerary keeps to the town centre and the lower valley, which are genuinely worthwhile and considerably kinder to post-marathon legs. The mountain palaces will still be there.
December in Sintra: The Serra de Sintra in December is frequently misty and cool (8--12°C), which suits the place architecturally. The romantic historicism of the 19th-century palace-builders was specifically inspired by northern European atmospheres, and the winter mist on the forested hillsides is the intended context for all of it. The summer crowds are largely absent in December.
Getting There
Rossio station is the historic central station in Lisbon, recognisable by its horseshoe-arch facade on Praça Dom Pedro IV (Rossio square). The station is on the Green Metro Line (Rossio stop) and within walking distance of Chiado and the Baixa. The Linha de Sintra departs from ground-level platforms.
The Palácio Nacional de Sintra
The Palácio Nacional de Sintra sits at the top of the village, identifiable from the valley by its two enormous conical kitchen chimneys. It is the oldest surviving royal palace in Portugal, continuously occupied from the 14th to the early 20th century. The interior rooms are largely at one level once inside: the Sala dos Brasões (ceiling painted with the coats of arms of 72 noble families), the Sala das Pegas (over 130 magpies painted in response to a court scandal), and the vast Sala dos Cisnes with its swan-ceiling. Book entry in advance at parquesdesintra.pt.
The walk from the station to the palace takes about 15 minutes on a moderate uphill road. A local bus or the Scotturb tuk-tuks waiting outside the station cover the climb in minutes if the gradient is unwelcome.
Vila Sassetti Gardens
The Vila Sassetti gardens, a short walk from the station along the valley floor, are a 19th-century private estate now open to the public. The garden paths follow the lower valley at a gentle gradient, passing under a canopy of tree ferns, camellias, and the specific vegetation of the Serra de Sintra microclimate. In December, the camellias are beginning to bloom. This is the genuinely flat alternative when the legs want minimal effort.
Where to Eat
Queijadas de Sintra - small round pastries of fresh cheese, sugar, and cinnamon in a crisp shell - have been made in the town since at least the 13th century. Buy them from the bakeries near the palace rather than the tourist shops at the station. For a full meal, the restaurants on Rua João de Deus in the historic centre serve reliable Portuguese cooking; the winter menus run toward braised meats and stews, which is the appropriate December lunch.
Getting Back
Linha de Sintra trains return to Rossio every 20 minutes. There is no urgency about the return time.