The French presidential wine cellar holds 14,000 bottles regarded as so precious, few people are allowed to enter the room. Flower bouquets are displayed at the presidential palace only for a couple of hours so they always look fresh. And the president's chefs use 150-year-old copper pans.

These and other behind-the-scenes quirks of the Elysee Palace are getting a rare airing this weekend, when the home of French presidents since 1848 opens its heavy and usually tightly closed doors to a small, but lucky group of ordinary citizens.

On Saturday and Sunday, a few hundred people were visiting the underground kitchen, cellar and florist rooms.

They were able to buy souvenirs from a new boutique to help finance palace renovations expected to cost 100 million euros ($117 million) over the next seven years. Across France, other usually closed sites are also opening their doors for the weekend as part of European Heritage Days.

Under President Emmanuel Macron's office and the Elysee's 18th-century golden reception rooms is an underground world where a small battalion of workers makes the whole place tick. They labor out of sight in a maze of austere corridors and narrow rooms with artificial light and gray and beige walls.

Every morning, the basement comes to life when fresh produce, fish and meats are delivered to the kitchen and checked for quality. Most of the food — except items like coffee and chocolate — is sourced in France.

The kitchen staff of 28 people, plus apprentices, serves 92,000-95,000 meals per year. They cook daily for Macron and his wife Brigitte and for some Elysee employees, and handle official dinners, big events like receptions at the Chateau of Versailles west of Paris and prepare in-flight meals for the presidential plane.

Presidential tastes and menus remain one of the best kept secrets of the Elysee.

Chef Guillaume Gomez wouldn't answer questions about the Macrons' meals. The French leader once said his favorite dish is blanquette de veau, a traditional veal stew in creamy white sauce.

"Unlike a restaurant, we work on a daily basis with the seasons, the activity and news events of the president," he said.

The basement kitchen used to be a horse stable. It was converted at the end of the 19th century and renovated in 1989.

A full set of copper pots and pans from 1845-1865 hang on the wall and are used daily.

Gomez said the copper would corrode if the pans were idle. "If it's not used — heated, cooled down, heated, cooled down — it dies," he said.

Plus, buying a modern stainless steel replacement set would cost several hundred thousand euros.

From the kitchen, a dark corridor leads to one of the most protected places of the Elysee: the wine cellar.

A first room presents a selection of classic wines for working lunches and dinners and a selection of aperitif drinks. The second cellar, much bigger, is protected by a locked door. Higher quality bottles are stocked there and all visitors are banned from entering.

The head sommelier's mission is to select wines that fit with the chef's menu and to buy the finest vintages to replace them: exclusively French, of course.

The multiple underground corridors seem like a labyrinth to outsiders. But the smell of flowers points the way to the florists' rooms.

Three people prepare flower table centers that will then systematically be re-used in other bouquets. The flowers are only displayed when needed for an event, and then immediately go back into cold storage in the Elysee basement.

Flowers come from France and other producers like the Netherlands and Ecuador.

Marianne Fuseau, head florist, explained that flowers are matched to suit the tablecloths and tableware "to avoid any bad taste."

She also checks the colors don't clash with the clothes worn by visiting heads of state. She uses roses but avoids lilies, too fragrant, and mimosas, because they can provoke allergic reactions.

About 340 people registered on the Elysee website to visit the palace.

The presidency's just opened online boutique sells branded mugs, pens, T-shirts and other products to help finance palace renovations.

A watch with a red-white-and-blue wristband and a tote bag marked "Premiere Dame" ("First Lady") are among the items. All the goodies are made in France.

European Heritage Days, also called Heritage Open Days, are held every September, with many monuments and sites across the continent opening to the public free of charge. The program was launched by the Council of Europe in 1985, and in 1999 the European Union joined in.