The palace was then occupied by King Carlos I and Queen Consort Amelia of Orleans who used it as a summer residence until Portugal became a republic in 1910. It is now the National Palace of Pena and a major tourist attraction in Portugal, with up to 800,000 people visiting a year.

The Park and National Palace of Pena in Sintra, Portugal, is one of the most visited monuments in the country, typically drawing over 1 million visitors annually. As of 2026, the site has implemented extremely strict crowd-control measures to preserve the 19th-century Romanticist structure and manage the heavy tourist flow. Visitors are now required to book timed entry slots in advance, and the palace frequently reaches its daily capacity during the peak summer months. In response to the overwhelming popularity, a new "Park and Palace" management system was launched in April 2026, offering specialized theatrical and guided visits to spread crowds across the 200-hectare park. On peak days, the palace can see several thousand visitors, but the timed entry system ensures that the number of people inside the actual interior rooms at any one time is strictly limited to prevent damage and improve the guest experience.