Yes, Sintra is extremely touristy in 2026, often cited as one of the most crowded destinations in Portugal. Due to its proximity to Lisbon, it is flooded with day-trippers who congregate at the "Big Three": Pena Palace, Quinta da Regaleira, and the Moorish Castle. During peak summer months, wait times for the 434 tourist bus can exceed an hour, and the narrow historic streets can feel like a "bottleneck" of humanity. To enjoy Sintra's "fairytale" magic without the stress, experts recommend arriving by 8:30 AM—before the first trains from Lisbon arrive—and visiting the monuments in reverse order. Alternatively, you can explore "hidden gems" like Monserrate Palace or the Capuchos Monastery, which are equally beautiful but see a fraction of the crowds. In 2026, booking "timed-entry" tickets for Pena Palace at least two weeks in advance is mandatory, as the site now strictly limits daily visitors to prevent the overwhelming "overtourism" that has plagued the town in recent years.