If you’re in Paris this weekend, you’re in for a treat … a.k.a the annual Heritage Days.

If not? Schedule a future holiday to coincide with the third weekend of September, for this is when Paris (and the rest of France) celebrate the Journées du Patrimoine.

On these Heritage Days, many historic yet private buildings open to a curious public, while other cultural institutions celebrate the country’s rich history by hosting talks, workshops, guided tours and artistic performances.

To find out what’s on in Paris this weekend, click here. (Note: some events require registration.) And read on for a few highlights …

Bibliothèque Nationale de France — Inauguration of Richelieu Site

Perhaps the most anticipated event of the coming weekend, for history and literature lovers alike, is the official reopening of this storied library site, after twelve years of renovation. Wander through the beautifully refurbished rooms, while being entertained by dancers, singers, actors and comedians, admiring the décor as you go. The library complex, which occupies a city block just north of the Palais Royal, dates back to the seventeenth century. It has changed much since then, although you can still admire evocative seventeenth-century brick-and-stone façades, newly restored and bright, as well as sparkling Baroque and Rococo interiors.

The new Musée de la BnF occupies a series of glamorous rooms, including the famed Galerie Mazarin (above). Within these lavish spaces, all sorts of gems are on display — famous manuscripts (Victor Hugo, Marcel Proust, Simone de Beauvoir), as you’d expect to see in a Paris library museum, but also priceless, ancient treasures such as a chess set that once belonged to Charlemagne and Dagobert’s bronze throne. Also open once more: the Salle Ovale, the majestic reading room that was first unveiled in 1936 …

If you miss a visit this weekend, the Oval Room will remain open to the public, and you can buy tickets to the museum here. Entry is via 5 Rue Vivienne, where there is now a lovely palm tree-shaded garden for anyone to enjoy, and a new addition to the museum café scene, thanks to Rose Bakery.

Guided Tour of the Hôtel de Rohan & Chancellerie d’Orléans

If you’ve been to the Musée des Archives Nationales, where you likely swooned over the Rococo interiors of the former Hôtel de Soubise, you might have, as you wandered about the gardens, noticed the rear façade of a rather grand building …

This is the old Hôtel de Rohan, one of the most spectacular Parisian palaces of the eighteenth century. It has been under wraps for a few years now, as a team of restorers have worked to refit its ground floor with a series of rooms from another stunning eighteenth-century townhouse, the Chancellerie d’Orléans, which was demolished in 1923.

This weekend is a chance for a sneak peek at the results, in advance of the public opening (the timing of which is still to be confirmed).

The interiors, dating from a time when Neoclassical was nudging out Rococo, had been cut up and placed in storage, and their rebirth comes after years of campaigning by French heritage groups and figures, as well as a mammoth jigsaw puzzle of a job for restorers, who had to put back together 10,000+ cornices, consoles, freizes, garlands and so on.

The tour also takes in a succession of upstairs rooms, which date back to the era of the cardinals of Rohan, and are happy to remain revelling in Rococo glamour.

Photographed above are the famous Cabinet des Singes (at top; note the sweet painted monkeys) and Cabinet des Fables, which are surely all the more exquisite in person.

Visit to the Banque de France (Hôtel de Toulouse)

One of the reasons for the demolition of the aforementioned Chancellerie d’Orléans was to make way for the ever-spreading Banque de France complex. (By the way, in a happy example of architectural karma, the restoration of those Chancellerie rooms was funded by the Banque de France, along with the World Monuments Fund and the French Ministry of Culture.)

Much of the land that now holds the Paris headquarters of the Banque de France is covered with an architectural hodge-podge, tweaked over time, but the garden wing of the seventeenth-century townhouse, the Hôtel de Toulouse, remains, and its usually-private Galerie Dorée — another example of Rococo exuberance like only Paris knows how to do — is open this weekend (along with some other rooms). It’s a must-visit for all who forever walk around this city’s streets, dreaming of the colourful gorgeousness that lies behind the beige walls.

Visit to Hôtel de Talleyrand (Georges C. Marshall Center)

Continuing the theme of Rococo … the Hôtel de Talleyrand, rarely open to the public these days, is also rolling out the figurative red carpet. The one-time townhouse was built in the 1760s — and is a perfect example of Louis XV style — but is named after a later inhabitant, the famous diplomat Charles-Maurice de Talleyrand-Perigord.

As you wander about the sparkling rooms, where you can easily imagine how the power of soft diplomacy played out in the past, thrill to the knowledge that this was where the Marshall Plan — the post-war American initiative to stimulate the economies of a devastated Europe — was nutted out. Since 1947, this sublime building has been owned by the United States government, which financed the restoration, along with the World Monuments Fund, of the glittering rooms now collectively known as the George C. Marshall Center, returning them back to their original colour scheme, an eye-pleasing palette of white, gold and grey.

Visit to the Palais du Luxembourg & Petit Luxembourg

Let’s head down to the Left Bank for one more heritage highlight … The Jardin du Luxembourg is home to Marie de Medici’s grand old digs, now the Upper House of the French Parliament and, as such, out of bounds to snoopers. So this weekend is your chance to finally see what’s inside.

Most of the queen’s vision is long gone, but much of the interior, reworked in the first half of the nineteenth century, is stunning nevertheless — the glossy library that was painted by Delacroix, no less, and the Salle des Conférences (above), an extravaganza of red and gold that would set the tone for the opulent Second Empire era.

You’ll also get to wander through neighbouring Petit Luxembourg (above), a townhouse that can trace its story back to 1550. Again, not much from then remains, but you can see remnants of a convent Marie installed here in 1622: the cloister, now a Winter Garden, and the Queen’s Chapel. You’ll also be able to admire the pretty early-seventeenth-century rooms of one of France’s most lauded Rococo designers, Gabriel Germain Boffrand (who, incidentally, was the man behind the Chancellerie d’Orléans), along with his grand swoop of a staircase, beautifully and classically rendered in stone.

The tour also grants access to garden’s greenhouses, where you can view the luscious fruit and orchid collections. A fitting way to end a fruitful weekend, non?