The royal palace evolved in stages, rebuilt by Dom Joao I in the early 15th century; then by his successor, King Manuel I, who lent his name to the Manueline architectural style.
The result is connected buildings, towers and cloisters of distinct styles: Moorish, Gothic and Manueline. The signature feature is the Arabic-style twin chimneys, 33m high, built to reduce the fire risk from the huge kitchens.
Inside are ornately decorated state rooms and royal bedrooms. There's the Swan Room, with its ceiling of 127 decorative swans, and the Magpie Room - the ceiling painted with the emblem of King Joao I and the walls covered in rose-patterned tiles to please his wife, Philippa of Lancaster, whose symbol was the rose.
The Galleon Room features an arched ceiling lined with ships to acknowledge Portugal's maritime dominance in the 16th and 17th centuries. In the western tower is the Blazon's Hall, where the ceiling is gilded woodwork emblazoned with the coats of arms of 72 noble families.
But even the diversity of the National Palace cannot compare to what's up the hill, the Pena Palace, built to the instructions of King Ferdinand II in the 1840s. Known as the Artist King for his own dabblings and for his support of the arts, Ferdinand, an Austrian who married Queen Maria II, was seduced by Sintra when the queen brought him here.
He eschewed the National Palace in favour of building an extravagant, Romantic-style affair.
Eclectic does not do justice to Pena: part military-style fort, part palace, it resembles a Disneyland mock-up of a Bavarian castle, and the melange of influences is not to everyone's taste.
It's fun, though it does pay to have a guide to get the in-jokes and the many references to other Portuguese buildings and architecture Ferdinand admired. The entrance is a nod to medieval times with merlins, a drawbridge, Moorish arches and minarets. There are Gothic touches, serpent motifs and wolfskins to denote he was a freemason.
The chapel replicates one built in Lisbon to honour the explorer Vasco da Gama but destroyed in the earthquake of 1755. Ferdinand bought the chapel ruins and reconstructed it.
A triton (half-man, half-fish) portico, designed by Ferdinand, guards the palace entrance, with aquatic motifs alluding to Portugal's seafaring exploits. Inside, decorative elves, fruit, and pigs greet visitors, bringing the outside in, in the Manueline way. Our guide suspects the king probably believed in elves.
In the cloister, the centrepiece is a New Zealand tree fern. The palace rooms and chambers are filled with period furniture, the walls and ceilings tiled or painted to replicate Moorish stone. The dining room furniture is carved with animal motifs, the centrepiece a silver galleon lamp.
The tower houses the chambers of King Manuel II, the last king of Portugal. It's a place as magical as its setting - the surrounding forest was landscaped with more than 200 species of tree from around the globe.
Ferdinand financed the entire project himself, also buying and restoring the remains of the nearby Moorish castle, which offers perhaps the best vantage point of the palace.
CHECKLIST
Getting there: Emirates flies three times daily from Auckland with all flights providing a direct connection at Dubai with Emirates' daily service to Lisbon.
* Geoff Cumming travelled as a guest of Emirates Airlines and Tourism Portugal.
