It was, apparently, Huayna Cupac, the Inca ruler who finally conquered Ecuador, who built a palace here around 1440. I can easily imagine him gazing at the spectacle of Cotopaxi, and quaffing a cup of chicha, their fermented corn drink, in honour of Apu, the spirit of the mountains.
Much of that palace still stands today. Huayna Cupac's temple, built in Inca-fashion in blocks of stone that fitted so well they didn't need mortar, is now the hacienda chapel. Another Inca building is the dining room. And archeological investigation is revealing more Inca remains all the time.
Wander around with the present owner, Mignon Plaza, and treasures appear everywhere.
"We had the archaeologists here again last month," she says, "and they made several discoveries which indicate it was even more important than we first thought."
No wonder San Agustin is recognised as one of the two most significant Inca sites in Ecuador. But its history doesn't stop there.
After the Incas were overthrown by the Conquistadors, in 1590, the King of Spain gave the land to the Augustinian order, which incorporated the Inca palace into a Spanish-style farmhouse, a base for their mission to convert the local people.
During its centuries as a monastery it provided accommodation for some of the most distinguished visitors to Spanish South America.
The names may be little known in New Zealand, but they included German naturalist Alexander von Humboldt, Spanish geographers Jorge Juan and Antonio de Ulloa, who were members of a geodesic mission that helped establish the shape of the earth, French scientist Charles-Marie de la Condamine and British explorer Edward Whymper.
Then when Ecuador gained its independence, San Agustin became a private estate, and in 1921 was bought by the Plaza family, one of the most distinguished names in Ecuador.
Mignon's grandfather General Leonidas Plaza, greatly beloved as leader of what Ecuadoreans call "the liberal revolution", was president from 1901-05 and 1912-16, her uncle Gala followed him in 1948-52, while her father Jose Maria served many years as an influential congressman and was also famous as an amateur bullfighter.
And it so happens that the suite I was occupying, the Mulalo Suite, with three rooms and three fireplaces, all blazing merrily away, was where her father lived, and his father before him. No wonder I slept soundly.
These days, the hacienda is a hotel, and its centuries-old tradition of hospitality continues. When Mignon heard we were from New Zealand, she immediately arranged for a local group to bring their panpipes, drums and charango (a stringed instrument) and give us a taste of Andean music. And when we praised the delicious traditional potato soup (locro) served at her table, nothing would do but we had to troop to the kitchen for a demonstration of how to make it.
One of the reasons for the Inca lords - and others down the years - coming to this place is its remarkable setting with vast fertile plains ideal for grazing animals or growing crops presided over by spectacular mountains.
We got a closer feel for the region's farming history at another Andean hacienda, Hacienda la Alegria, which follows an ancient tradition of raising horses, cattle, fighting bulls, llamas and vicuna, keeping alive the proud tradition of the chagras (Andean cowboys).
These days, they also take tourists on horse treks in the high grasslands and forests where, as owner Gabriel Espinosa boasts, "you can ride for a month without ever seeing a fence".
And we saw the mountains up close during a visit to the Cotopaxi National Park which lies around the flanks of the massive volcano.
This is rugged country but with plenty of wildlife. Driving through the park we passed herds of llama and horses grazing in meadows littered with huge volcanic bombs and flocks of water birds feeding on the waters of the Limpiopunga Lagoon.
At Tambopaxi Lodge in the middle of the park, where we stopped for lunch, owner Belisario Chiriboga had tales of even more spectacular animals.
"I've never seen a puma but I know they are here because one killed a llama just over there," he said, gesturing in the direction of Cotopaxi. The park rangers came to tell me.
"Mostly the pumas stay over the other side of the park but when they are hungry they come here ... . sometimes I've seen foxes, condors and wild bulls ... "
But the park is dominated by the mountains. Cotopaxi was hiding behind the clouds the day we visited but it did peek out long enough for us to see the spectacular red patch left by the melting of a once massive glacier on its eastern face.
The most spectacular sight, however, came as we left the lagoon and Cecilia, our guide, suddenly gave an excited shout. "Look. Look there. Chimborazo."
We looked, and there, sure enough, was a vast snow-covered mountain.
"That is amazing," she said. "It is always behind the clouds. We only see it like this maybe once a year."
Chimborazo, which towers 6268m above sea level, is an extinct volcano which last erupted some 1500 years ago.
Because of its size the mountain is regarded by the indigenous Andeans as the father of the Andes and its name is generally thought to mean "throne of god".
I later discovered that until the early 19th century Chimborazo was considered to be the highest mountain on earth, and was first climbed in 1880 by Edward Whymper, the chap we met at San Agustin.
These days, Mt Everest is known to be the world's highest peak, but Chimborazo still has one claim to fame. Because of the bulge in the earth around the equator, its summit is the furthest point from the centre of the earth, 2.1km further than Everest.
Mignon Plaza's Ecuadorean Locro (potato soup)
1. Saute a diced spring onion and lots of chopped garlic in butter.
2. Cut potatoes (must be agria or another very dry variety) into different sized chunks, leaving some whole, and saute them in the butter and garlic so they absorb the taste.
3. Add hot water and cook until the potatoes are soft.
4. Pour off the liquid - putting the potatoes aside - add some milk with two kinds of soft fresh country cheese and blend until the soup has a creamy texture.
5. Return the potatoes, put a bit of grated cheese on top and eat with avocado and aji (the Ecuadorean hot sauce).
CHECKLIST
Getting there: LAN Airlines flies daily from Auckland to Santiago with onward connections to Quito or Guayaquil in Ecuador.
Getting around: World Journeys offer an eight-day Haciendas and History package in Ecuador, visiting the capital city of Quito, the Otavalo markets, rural craft villages, Cuicocha Lake and Cotopaxi National Park. Price includes hacienda and other five-star accommodation, transport, sight-seeing and entrance fees with local English-speaking guides and most meals. Phone 0800 11 73 11.
Where to stay: Try Hacienda San Agustin de Callo, Hacienda la Alegria or Tambopaxi Lodge.
Further information: See ecuador.travel.
Jim Eagles went to Ecuador with help from Lan Airlines and World Journeys.
