With its bright yellow exterior and fairy-tale turrets, Pena National Palace (Palacio Nacional da Pena) frequently tops the list of the best UNESCO sites in Lisbon, and is the crowning glory of Sintra’s architectural feats. Its hilltop perch and extravagant mix of Moorish, Gothic, Egyptian, and Renaissance elements make you feel as though you’ve stepped into Alice in Wonderland.

When it comes to monasteries, Portugal really knows its stuff: Alcobaça Monastery (Mosteiro de Alcobaça) is one of three UNESCO–listed monasteries in the country. Because construction began in the 12th century, this is one of Portugal’s first Gothic buildings. Inside, focal points include the elaborate Hall of Kings and interiors hailed as masterpieces of Gothic Cistercian art.

One of the top UNESCO World Heritage sites in Lisbon, the Monastery of St. Jerome (Mosteiro dos Jeronimos) is one of the capital’s most elaborate buildings. Highlights of the structure include the tomb of renowned explorer Vasco da Gama, a library containing centuries-old manuscripts, and the intricate stone carvings and stained glass windows of the Church of Santa Maria. After exploring the monastery, stop at the neighboring Pastéis de Belém to taste Lisbon’s famous custard tarts.

Once you’ve finished your inner-city Lisbon UNESCO Heritage tour, head a little farther afield to one of the country’s most impressive architectural examples. The official resting place of Portuguese royalty, Batalha Monastery (Mosteiro da Batalha), has Gothic features and dramatic arches dating back to the 14th century; highlights include the cloisters and Founders Chapel.

No Lisbon World Heritage sites guide would be complete without mentioning Belém Tower (Torre de Belém), a 16th-century stronghold that once protected Portugal from enemy ships. The structure is a stunning example of Renaissance architecture and features a rooftop terrace from which you can admire seemingly endless views of the Atlantic Ocean.

Hailed as a masterpiece of Romanticism, Monserrate Palace (Palacio de Monserrate) is a highlight of Sintra’s UNESCO–listed landscape. Islamic-inspired design melds with Indian and Gothic styles in this architectural melting pot, which is also home to stained glass windows, a sacred art Room, and a music room featuring an elaborate cupola. But the wonders aren’t just inside; the palace is surrounded by stunning grounds featuring a Japanese garden, a valley of ferns, and even a waterfall.

With roots dating back to the 15th century, the Évora historic center is a UNESCO World Heritage Site with a difference. While the ruins of a Roman temple and the gorgeous Giraldo Square exemplify the town’s rich heritage, its most fascinating attraction is undoubtedly the Chapel of Bones (Capela dos Ossos), made entirely from human skulls and bones. Sacred and spooky, this church and its surrounding attractions make Évora a must-visit attraction for history buffs.

Shrouded by the lush, green Sintra Mountains, the Castle of the Moors (Castelo dos Mouros) reigns over landscapes from its hilltop perch. Dating back to the 9th century, the semi-ruined castle features textbook castle turrets and a tombstone carved with a crescent moon. But the real draw of the landmark is the views, which stretch from Sintra to the Atlantic Ocean. Combine the castle with other Sintra standouts on a private tour that lets you explore at your own pace.

Just a 2-hour drive from the capital is Coimbra, home to the 13th-century University of Coimbra (Universidade de Coimbra), one of the oldest universities in Europe. Nestled among the Baroque architecture of the educational complex, you’ll find the glorious Biblioteca Joanina, where ceiling frescoes and more than 40,000 books pay homage to reading. Just make sure to watch your head, as this library is home to a colony of bats that protect the books from insect damage.