MADRID.- There are few paintings in the world that invite viewers to linger quite like The Garden of Earthly Delights. At the Museo Nacional del Prado, that sense of fascination took center stage once again on April 5, as the museum marked its now-established Bosch Day with a fresh, technology-driven perspective on the iconic masterpiece.

The date is more than symbolic. It traces back to April 5, 1474—the first known written reference to Hieronymus Bosch, when he appeared as a witness in a notarial document in the Netherlands. What began as a historical footnote has evolved into an annual invitation: to slow down, look closely, and rediscover an artist whose imagination still feels startlingly modern.

A painting that refuses to reveal everything at once

This year’s celebration leaned into that idea of looking again—but with a 21st-century twist.

Under the project “Counting The Garden of Earthly Delights,” the Prado partnered with Sherpa.ai to analyze the painting using artificial intelligence. The goal was simple in concept, but ambitious in execution: to map the overwhelming visual density of Bosch’s triptych in a way the human eye alone could never fully achieve.

The results are striking:

• 1,451 total elements identified
• 667 human figures
• 771 animals
• 45 hybrid or fantastical creatures

Numbers, of course, don’t explain Bosch—but they do reveal just how much is happening within the painting’s layered scenes. From the serene beginnings of Paradise to the chaotic, haunting imagery of Hell, every inch of the composition seems alive with narrative.

Technology meets imagination

To reach these insights, Sherpa.ai deployed a system that blends general image recognition with highly specialized models trained to detect specific visual elements. In practical terms, this means the software can “read” a painting not just as a whole, but as a dense ecosystem of individual forms and relationships.

It’s a fitting approach for an artist like Bosch, whose work has always resisted easy interpretation. His worlds are intricate, symbolic, and often surreal—filled with creatures and scenarios that feel both playful and unsettling.

Rather than replacing traditional art historical analysis, the technology opens a parallel path: one that invites viewers to engage with the painting in a more exploratory, almost investigative way.

The enduring pull of Bosch

The Prado is uniquely positioned for this kind of experiment. Its collection includes some of Bosch’s most celebrated works, from The Haywain to The Temptations of Saint Anthony. But The Garden of Earthly Delights remains the centerpiece—a painting that continues to captivate audiences five centuries after it was created.

Interestingly, even language is catching up with Bosch’s influence. The term “Boschian,” used to describe strange, dreamlike, or fantastical imagery, has become so widespread that it now appears as a recognized entry on Wikipedia—evidence of how deeply his vision has permeated visual culture.

A day that keeps growing

Bosch Day itself is still relatively new, but it has quickly become a cornerstone of the Prado’s programming. In recent years, the museum has expanded the initiative beyond a single event:

• A dedicated online space exploring Bosch’s work and legacy
• The video At the Feet of Bosch, featuring dancer Eduardo Guerrero
• A proposal to formally incorporate the term “Boschian” into the Spanish language
• Collaborations with major European museums to amplify the celebration

Even earlier research has contributed to this evolving conversation. A 2023 eye-tracking study conducted with Miguel Hernández University revealed how viewers actually navigate the painting—often starting in Paradise before being drawn, almost inevitably, toward the darker, more chaotic scenes of Hell.

Looking closer, seeing more

What this year’s initiative makes clear is that Bosch’s work is far from exhausted. If anything, it continues to expand—each new tool, whether technological or conceptual, revealing another layer of meaning.

And perhaps that’s the real point of Bosch Day. Not just to celebrate an artist, but to remind us that some works of art are never fully seen in a single glance.

They ask us to return, again and again, each time discovering something we hadn’t noticed before.