Yes, visiting Sintra without a tour is not only possible but often preferred by travelers who want to explore at their own pace in 2026. The most efficient way to reach the town from Lisbon is by taking the train from Rossio Station, which takes about 40 minutes and costs less than €5. Once in Sintra, you can navigate the major sites like Pena Palace, the Moorish Castle, and Quinta da Regaleira by using the dedicated 434 tourist bus (Circuito da Pena) or the 435 bus (Villa Express 4 Palácios). While the town is scenic, the hills between monuments are extremely steep and difficult to walk, so relying on these public buses or local Tuk-Tuks is recommended. For a successful self-guided day, it is critical to pre-book timed-entry tickets online for Pena Palace, as lines are long and walk-up tickets often sell out. Planning an early arrival (before 9:00 AM) or a late afternoon visit helps you avoid the mass of tour groups that dominate the midday hours.