In the basement of Dresden’s Royal Palace, visitors stand in a line, two by two. Each pair is ushered into a spaceship-like air lock, where the doors shush closed behind them before another set glides open, depositing them in the Green Vault, a chamber of treasures amassed by the Baroque-period rulers of Saxony, the easternmost state in Germany.

If the security seems like something out of a Mission: Impossible movie, there’s a reason: the Green Vault’s 4,000-piece art collection, including jewelry dripping with priceless stones, was the victim of a high-profile, $119 million heist in 2019. (The 21 stolen objects were later found and returned.) With its renovations newly completed, the Royal Palace has taken center stage in the Dresden State Art Collections (Staatliche Kunstsammlungen Dresden, or S.K.D.).

The Green Vault, beneath Dresden’s Royal Palace.

One of the oldest and largest collections in Europe, the S.K.D. now has eight permanent homes around the city. Many of those have been rebuilt according to their lavish historic designs, which lay in ruins following the World War II bombings that reduced 90 percent of the city center to rubble. With funding from the German government, the Royal Palace, for example, has been brought back from the ashes as a four-winged mansion with slender patinaed domes and a newly reconstructed courtyard decorated in sgraffito.

“These buildings would probably not have been restored in such a painstaking way if they hadn’t been needed by the State Art Collections,” says Wolfgang Gärtner, head of international marketing for Saxony Tourism. The rebuilding has catapulted a city leveled by war into one of the most visited in Germany, and spearheaded a revival of arts and culture.

The S.K.D. began as the royal collection of Augustus the Strong (1670‒1733), elector of Saxony, who was inspired by the opulence of Versailles. It survived, largely unscathed, the Seven Years’ War (1756–63). Germany’s Ministry of Culture assumed oversight of the S.K.D. in 1919.

The Dresden Castle and Cathedral after the bombings of World War II.

The aerial bombardment of World War II, which targeted a Third Reich transportation hub in Dresden, presented a different challenge. Beginning in 1939, museum officials and volunteers packed up artworks and secreted them off to remote locations including Königstein Fortress, in the Elbe Sandstone Mountains, and Meissen’s Albrechtsburg Castle. Some pieces were hidden in “salvage depots,” such as limestone quarries and railway tunnels. These were seized by Soviet soldiers and kept in Moscow for a decade.

Even after the collection was finally re-united, in 1955, Dresden no longer had the facilities to display it. Portions were housed outside the city as the Saxon capital was rebuilt.

Today, the S.K.D. represents 1.2 million works in a wide range of time periods, from hand-formed Neolithic idols to 18th-century porcelain, works on paper, scientific instruments, puppets, and contemporary paintings. “The most important works,” says Marion Schmidt, of the S.K.D., “originate from the Renaissance, Baroque, and 19th century.”

The Sistine Madonna, by Raphael.

Such is the case for the Old Masters Picture Gallery, the most beloved sub-collection. Housed in the recently reopened Zwinger, it includes paintings by Cranach, Canaletto, Vermeer, Rembrandt, and Brueghel. Raphael’s 1512 Sistine Madonna is its crown jewel.

Adam Szymanski, a Toronto-based art adviser, says, “These are all blue-chip artworks that would sell for well above $1 million, and sometimes tens of millions, if they were even available at auction.”

The Green Vault opened in 1723 as Europe’s first public museum and is now divided into two can’t-make-this-up sub-collections arranged in 6,000 square feet of space. Among the treasures of the Historic Green Vault—not just a museum but an expression of 18th-century excess and power—are carved-crystal bowls, elaborate precious-metal-and-gemstone dioramas by Dresden court jeweler Dinglinger, and a Renaissance-era cherry pit carved with 185 miniscule faces.

The Dresden Green Diamond.

The New Green Vault’s most famous resident is the Dresden Green Diamond, a hat ornament featuring a flawless, 41-carat, lime-hued diamond surrounded by brilliant-cut colorless stones. Wolfram Koeppe, the Marina Kellen French Senior Curator in the Department of European Sculpture and Decorative Arts at the Metropolitan Museum of Art, says, “Most single important jewels or precious stones have been moved to different places, or they end up being divided or reset—like the Hope Diamond. The fact that [the Green Diamond] is still there, in its original form, is something exceedingly rare.”

Back in the Historic Green Vault, three senior Dresdners cluster, heads nearly touching, around the Order of the Golden Fleece, a medal commissioned in 1477 by the House of Habsburg. They coo at the pin, which features plump rubies tucked within geometric arrangements of diamonds, a diamond-hoofed golden ram dangling from its bottom clasp.

For residents, where the S.K.D. ranks among museums is immaterial. But what it has done for their city is immeasurable.

Robin Catalano is a Hudson Valley–based journalist focused on travel, culture, and food