The Wave
A sand-printed sculpture that turned a stretch of Scheveningen beach into an exercise game.
At a glance
- Form
- 3D sand-printed in stacked segments, assembled on site
- Sensing
- Three movement sensors — no cameras, no images recorded
- Interaction
- Four games, chosen with four lit buttons on a sand-printed control post
- Environment
- Open beach. Salt air, blown sand, standing water, full temperature swing
- Supervision
- None. Unattended public use for the whole run
- Run
- Roughly 18 months, including a relocation along the beach, then removed as planned
Who it is for
- Municipalities placing one memorable object rather than a set of equipment
- Sites where cameras are politically or legally impossible
- Programmes aimed at people who walk straight past normal outdoor gym kit
What you can play
Jump the Light
The light travels around the sculpture and you jump above it.
Light Squats
Squat in front of it and keep a rhythm.
Light Boxing
Punch in front of the middle sensor.
Light Dance 2P
Two people move side to side and dance together.
All four in English and Dutch, chosen at the control post. No account, no app, no sign-up.
Where it fits
Beaches and waterfronts
A landmark people walk toward, that happens to make them move once they arrive.
Parks and plazas
A single sculptural object where a row of gym equipment would feel institutional.
Festivals and temporary programmes
Built in segments and lifted into place, so it can be installed and struck again.
Where it is the wrong call. A budget-conscious rollout across many locations. The Wave is a one-off sculpture — the form is the point, and the form is expensive. If you need twenty of something, look at CityGems instead.
The problem it was built for
Public exercise equipment has a self-selection problem. It is usually built for people who are already fit and already confident — so the people who would benefit most walk straight past it.
The Municipality of The Hague, with Beach Management, wanted the opposite on Scheveningen Sports Beach: something a nine-year-old and a seventy-year-old would both walk up to without hesitating, whatever their skill, strength or age.
The answer was not a better pull-up bar. It was an object strange enough that people came over to find out what it was.
Two constraints shaped everything
It had to sense people without watching them. The obvious way to build an interactive installation is a camera and some computer vision. On a public beach that is unacceptable — it turns play equipment into surveillance, and it makes the project a data-protection conversation instead of a sports one.
So: three movement sensors, no cameras, and no image ever recorded. Because it reads movement rather than identity, it behaved the same for whoever walked up, and every interaction stayed anonymous by construction.
It had to survive a beach. Salt corrodes, sand gets into everything, water stands where you did not expect it, and nobody is on site to reset anything. That constraint drove more of the engineering than the interaction design did — and it is why the sculpture is a stack of segments rather than one piece, with the electronics reachable without dismantling the whole thing.
Played with before it was built
Before anything was printed, the whole thing ran indoors as a rough column with an LED strip down the front. Latency, difficulty and whether a stranger works out what to do without being told are things you can only find by playing — and they are ruinously expensive to discover once the object is on a beach.
The electronics were built on the bench alongside it: sensor boards, LED modules, drivers and a stack of printed schematics.
How it was made
The Wave was 3D-printed in sand — a binder-jetting process that builds the form in layers of bonded sand, the way a printer lays down ink. It lets you make a one-off architectural shape with real weight and texture, rather than assembling something from standard parts that reads as municipal equipment.
The grey prototype standing next to the finished print shows what the process bought: identical geometry, completely different object.
It came out of the printer as a set of hollow segments, each one cured, wired and fitted with internal bracing before anything was stacked.
Then it was crated, moved, and stacked on site.
Commissioning happened where the thing actually lives, which for a fortnight meant a laptop balanced on a sculpture in the wind.
Because it was built in segments and lifted into place rather than cast into a foundation, it could be moved — and it was. Partway through its run the whole sculpture was relocated along the beach to Oostduinen, by the entrance to the Pier.
What you actually did with it
A companion post next to the sculpture carried the controls. It was sand-printed too, with four illuminated buttons and the instructions printed straight into the surface — in English and Dutch, with no screen, because a screen on a beach is a maintenance problem, and no app, because downloading something is a barrier at the exact moment someone is curious.
No account, no app, no sign-up. You walked up, pressed a button, and it started.
After dark
Which is when it does the other half of its job — being visible from a distance, and inviting rather than instructing.
What it proved
The Wave ran for roughly eighteen months in unsupervised public use, then came down at the end of its run as planned.
What it demonstrated did not come down with it. It settled the question everything since has been built on: that a durable, sensor-driven, camera-free installation holds up to real public use — not for a staffed weekend event, but for a year and a half on an open beach in Dutch weather.
That proof is the direct foundation for CityGems — the same sensing, the same outdoor engineering and the same position on cameras, spread across a whole city instead of one stretch of sand.