Flying over the Northamptonshire countryside in 1944, a Luftwaffe pilot took some routine aerial photos. As the camera clicked, perhaps he noticed a strange pattern on the ground. Maybe his eye was caught by oddly shaped hills or an unusual pattern of waterways. Or maybe he saw nothing more than 60 acres of scrub with a shell of a building in one corner.

Whatever he noticed, his pictures are now being used in the restoration of an architectural Sleeping Beauty. Lyveden New Bield, an Elizabethan garden lodge near Oundle, is the kind of place that people who have been there hug to themselves. It is their secret, a hidden delight lost in the middle of forest and meadows, and an evocative spot for a picnic.

When its creator, Sir Thomas Tresham, died in 1605 his building died with him. For 400 years Lyveden New Bield (meaning Build) remained as he left it, unfinished, roofless, floorless, with bare ashlar walls and no glass in its windows. Its innovative water gardens succumbed to scrub and bramble that is only now being cleared by the National Trust.

Lyveden was the Elizabethan courtier’s grand scheme. Begun in 1595, the cruciform or cross-shaped lodge was to be a celebration of his faith, containing layer after layer of religious meaning. Catholicism was built in. There are, for example, five sides to each bay, each measuring five feet, the number attributed to both Christ and Mary. Sir Thomas was a staunch Roman Catholic unlucky to serve a Queen both Protestant and paranoid. Her persecutions of non-conformists meant he spent a quarter of his life in prison. Fined for his faith, his fortune was eroded to the extent that he died Pounds 11,000 in debt. His eldest son died in the same year, locked up in the Tower of London for his role in the Gunpowder plot.

Lyveden was not just a religious retreat. Sir Thomas was a powerful and wealthy man, and he liked to show off, when he was not in prison of course.

Lyveden was not his main residence - that was the nearby Rushton Hall - it was his pleasure palace, designed to have a great hall for entertaining, not to mention bedrooms, parlour and buttery.

The kitchens were equipped with bake ovens, a huge fireplace for spit roasting and coppers for cooking fish - all built in as the house developed. They were top of the range, and they needed to be for Sir Thomas’s guests would have been hungry. Lyveden was constructed in an age when, for the first time, the gentry felt secure and prosperous enough to sacrifice productive land for recreational use, says Mark Bradshaw, National Trust manager of the lodge. “They didn’t have to put the house at the summit of a hill surrounded by defensive moats. They could choose anywhere in their estate, because there was a feeling of peace and calm in Britain. They had the opportunity and wealth to start being creative in their landscape and develop garden design.” Until then, he says, only the monarchy had been able to attempt anything on a grand scale.

According to Mr Bradshaw, Sir Thomas intended his guests to spend three to four hours experiencing his 60-acre garden. They were to leave the main residence and come up through pleasure grounds, rose gardens and earth-bank terraces edged with wild flowers. A walnut-tree walk cut through five acres of orchards, en route to the main rose terrace. Boats and punts were provided for trips on the man-made canals though guests could also stay on the shore to fish.

Then there were the “prospect mounts”, small hills with paths designed to take the ladies in their balloon-like farthingale dresses. All four of Lyveden’s prospect mounts still exist, as do the views of the deer park meant to excite Sir Thomas’s guests. Down from the mounts they might have meandered into the labyrinth, whose 400-year-old shadow in the ground was usefully recorded by that Luftwaffe pilot. Or they might have tried their hand in the outdoor bowling alley.

Eventually, guests would arrive at the garden lodge for a banquet. Banquets came to England in Henry VIII’s time. They were originally much closer in spirit to a picnic than the huge indulgent feasts they became. The word comes from the old Italian banchetto meaning bench and the first banquets were simply snacks eaten on a bench.

By Tudor times they had evolved into the final course in a meal. While the servants made the dining hall ready for music and dancing, the aristocracy went off to the banqueting house to nibble buffet-style on expensive sweetmeats, says Alison Sim, historian and author of The Tudor Housewife.

The modern-day equivalent is going on to the patio for coffee and chocolates while the hostess loads the dishwasher.

Banquets also involved an appreciation of nature. At Hampton Court, Henry VIII built his banqueting house beside the Thames on a 30ft mound constructed from 250,000 bricks. Guests made their way to the top on spiral pathways large enough for four people to walk side by side. Once there, they entered the Great Round Arbour, a three-storey house made almost entirely of windows and surrounded by gardens. Queen Elizabeth had a similar house built on the highest hill at Nonsuch Palace, near London. At Longleat, they didn’t bother with mounds, simply constructing their banqueting houses on the roof of the main hall. “The idea was that you got the best of everything: beautiful views, the best company, the finest food and wine,” says Ms Sim.

The sense of taste was delighted with elaborate sweetmeats. Sugar was a luxury - the more you had, the higher your status. Unluckily for their teeth, the Elizabethans also considered it medicinal and an aphrodisiac which added a certain frisson to the banqueting course. It was used to impress guests - and to entertain them.

The aristocracy were fascinated by jokes and tricks with food, says Ms Sim.

Cups, plates, playing cards, even miniature working cannons were constructed out of sugar-plate, a mixture of egg, sugar and gelatine that set hard.

Look-alike rashers or “collops” of bacon, made from ground almonds and sugar, slipped down nicely, as did “leche”. This dessert, a rosewater-flavoured milk jelly, was cut into cubes some of which were gilded. Once arranged on a dish, leche became a kind of edible chess board.

Marzipan was another favourite of hosts in pursuit of the “wow” factor. The almond paste was moulded into animals, fruits, birds and baskets. It could also be iced and decorated, sometimes with crystallised fruits and sugar figurines.

Perhaps fortunately for their health, Sir Thomas’s guests at Lyveden would have dined on more than sugar. After their exertions they would have been served up an evening meal of spit-roasted meat, meat, and more meat (unless it was on a day that the Government ruled everyone had to eat fish to ensure seafaring skills survived).

Fruit was also popular, though the rich were a little wary and tended to prefer it cooked. Raw cherries, however, were a delicacy. Sir Thomas, a clever and efficient landowner, took both pleasure and profit from his orchard with its 300 pear, apple, damson, walnut and cherry trees. He would have been distressed to know that his wife had the whole lot dug up and sold four years after his death to try to clear her debts.

Now the orchard is growing again. As part of the reawakening of Lyveden, a major project that began eight years ago, the National Trust replanted it using the original varieties. They knew where to put the trees thanks to those Luftwaffe photos that revealed the holes where they had grown. The canals that weave in and out of the woodland were de-silted in 2000.

At night bats emerge from the roofless banqueting house to feast on flies hovering over the water. During the day kingfishers and dragonflies make themselves at home. As you watch them from the comfort of your picnic rug, spare a thought for Sir Thomas who created the garden, but did not live to enjoy it.