"Sintra Castle" usually refers to the Pena Palace, and in 2026, it is absolutely worth it, provided you manage your expectations regarding crowds. The palace is a masterpiece of 19th-century Romanticism, featuring a whimsical blend of Neo-Gothic, Neo-Manueline, and Islamic architectural styles painted in vivid yellows and reds. The views from the ramparts overlooking the Atlantic Ocean and the surrounding Sintra-Cascais Natural Park are unparalleled. However, because it is one of Portugal's most popular attractions, it can feel like a "tourist trap" if you visit during midday. To make it worth your time, you must book a timed-entry ticket weeks in advance and aim for the earliest morning slot. The interior is fascinating, filled with royal artifacts and preserved living quarters, but many visitors find that the true magic lies in exploring the vast, forested Pena Park that surrounds the castle. If you appreciate architecture that looks like a fairy tale come to life, there is truly no other place in Europe quite like it.