The colorful castle in Sintra, Portugal, is the Pena National Palace (Palácio Nacional da Pena). Perched on a high peak in the Sintra Mountains, it is world-renowned for its vivid yellow and red facades, which serve as a prime example of 19th-century Romanticist architecture. Interestingly, for much of the 20th century, the palace appeared entirely gray as the colors had faded; it was only repainted and restored to its original "fairy-tale" brilliance in the late 1990s. In 2026, the palace remains a UNESCO World Heritage site and one of the "Seven Wonders of Portugal." Visitors must now pre-book specific time slots to manage the massive crowds. The site features a mix of Neo-Gothic, Neo-Manueline, and Neo-Islamic styles, all surrounded by a 200-hectare park filled with exotic plants brought from the former Portuguese colonies.