Grand complication watches are the boss levels of horology. Not just because they’re difficult to make—but because they represent everything traditional watchmaking stands for. They’re the equivalent of writing an epic novel in iambic pentameter, by hand, backwards. The people who make them are freakishly skilled. The people who buy them? Usually billionaires with a deep-rooted obsession, or at least a brand relationship longer than most marriages. Which brings us to Anant Ambani—one of the few Indians spotted wearing the Patek Philippe Grandmaster Chime, a ₹66 crore behemoth with twin faces and 20 complications, making it one of the most technically advanced watches ever produced. It’s not just a flex. It’s a statement of belonging to a club so elite, most of us don’t even know where the door is.

Well, if Anant’s looking for his next watch, we’ve got a recommendation.

Unveiled at Watches & Wonders 2025, the Vacheron Constantin Les Cabinotiers Solaria Ultra Grand Complicationhas just taken the crown as the most complicated wristwatch ever made. With 41 complications, 13 patents, 1521 components, and five rare astronomical functions—including one never seen before—the Solaria isn’t just a watch. It’s a masterclass in what happens when watchmaking is treated like an artform without limits.

Eight Years In The Making

Vacheron’s no stranger to horological madness. In 2015, they unveiled the Reference 57260, a one-off pocket watch with 57 complications and a rumoured price tag between $8–20 million USD. It was the most complex watch in history—but not exactly wearable.

In recent years, we’ve seen other contenders in this extreme space. The Berkley Grand Complication, created by Franck Muller, held headlines in 2023 for its sheer audacity: 23 complications including a tourbillon, minute repeater, and a full perpetual calendar—plus a fully diamond-set exterior. But it was a commission, made for a private collector. As technical as it was, it wasn’t a pure expression of watchmaking ambition. It was a luxury request, fulfilled.

The Solaria, on the other hand, is different. Unlike the Berkley, which was made on demand, the Solaria is a fully Vacheron-driven project. One watchmaker—yes, just one—was given carte blanche to go absolutely wild and create the most extraordinary feat of horology possible. No budget, no limits. The result? Eight years of obsessive craftsmanship, with the sole instruction: make the most complicated wristwatch the world has ever seen. Even more interestingly, the Solaria is for sale. While there’s no official price tag, the watch is listed as “La Première”—a signal that this is only the first of its kind. Future examples can be ordered, with slight modifications to ensure each remains unique.

What Does It Look Like?

Despite housing 41 complications, the Solaria wears with restraint. At 45mm in diameter and just 14.99mm thick, it’s slimmer than you’d expect. One side displays civil and calendar time, while the reverse is a full-blown astronomical instrument. The case is 18K white gold. The movement—Calibre 3655—is a feat of mechanical architecture, split into two layered sections and linked by a patented “plug and play” connection system that lets the astronomical module be removed without disassembling the base.

It’s this miniaturisation—1,521 components packed into something you can wear daily—that makes the Solaria astonishing. Even the dials are built like technical sculptures, using ultra-thin sapphire discs (0.18mm) for things like moonphases, tides, sun height, and sunset times. On the back, a rotating sapphire disc displays the celestial vault overlaid with sidereal time.

The finishing is appropriately obsessive: nine different decorative techniques including bevelling, mirror polishing, sandblasting, and graining—all done by hand.

The most mind-bending function? One of the most fascinating combinations is the use of a column-wheel split-seconds chronograph as an astronomical tool—a world-first complication (pictured above). On the back, the chronograph sits over the celestial chart. You pick a star, start the chrono, and stop the first hand when it hits a reference point. The second hand continues until it reaches the star’s location on the chart. The green triangle in the centre then tells you how many hours remain until that star will appear overhead.

It’s deeply complex, wildly elegant, and arguably the most poetic use of a split-seconds chronograph we’ve ever seen. This works in tandem with a sapphire caseback displaying the celestial equator, ecliptic, and real-time motion of constellations based on your location and month. Vacheron filed a patent to reduce friction and vibration in this assembly—a move that also boosts chronograph accuracy.

Let's Talk Complications... Lots of Complications

The Solaria’s 41 complications span civil, solar, and sidereal timekeeping, musical chiming, advanced astronomy, and world time. Each is refined, integrated, and—despite the density—shockingly legible. While explaining how each one of these works will take far too long, here's a look at the entire list of functions crammed into the watch's compact frame:

Civil Time & Calendar:

• Hours, minutes, seconds

• Second time zone with day/night indicator

• World time for 24 cities

• Gregorian perpetual calendar with day, date, month, year, leap year

• ISO week number

• Four-digit digital year

• Power reserve

Chiming Mechanism:

• Westminster carillon minute repeater (4 hammers, 4 gongs)

• Hour, quarter, and minute strikes

• Repeater mode selector (hours only or full)

• Hammer rebound dampening

• Enhanced resonance architecture

Chronograph:

• Split-seconds chronograph

• 60-minute counter

• Column wheel

• Isolator to reduce amplitude loss

Astronomical Functions:

• Moonphase (accurate to 122 years)

• Mareoscope with spring/neap tides

• Sunrise and sunset times

• Length of day and night

• Solar culmination (noon)

• Equation of time

• Sidereal time

• Declination of the Sun

• Height and position of the Sun

• Celestial chart

• Zodiac calendar

• Solstices and equinoxes

• Meridian passage

• Star appearance timer via chrono

Others:

• Tourbillon

• Sidereal geartrain

• Multi-cam dual-sided function wheel

The most staggering thing about this watch isn’t just the engineering, or even the audacity of its features. It’s the fact that in 2025, Vacheron Constantin still believes in building something this complex. That one watchmaker spent eight years building a watch for no client, with no budget, simply because it was possible. In an era of AI-driven design and algorithmic speed, the Solaria Ultra Grand Complication stands as a handmade answer to the question: What happens when you aim for the absolute limits of what’s possible in mechanical watchmaking? I think Vacheron's work does the talking by itself.