There are places I remember vividly from our 2016 trip to Puerto Rico.
There are places I photographed because I knew, even then, that there was something special about them.
And then there is the nuclear reactor.
Apparently, I could stand near an experimental Cold War nuclear facility, take a few pictures of it, jot down two sentences in my journal, and then carry on with my day.
Past me had priorities.
In my defense, we were on our way to a lighthouse.
But nearly ten years later, when I returned to those old photographs and journal entries for Travel Made Personal: TMP Origins, I discovered something wonderful:
I had almost completely overlooked one of the strangest historical sites from our entire Puerto Rico trip.
And, just to make things more interesting, the little bit of history I did record about it was wrong.
An Unexpected Stop Near Rincón
On Monday, May 9, 2016, my son Zack and I were staying with my parents in Puerto Rico.
Our morning started quietly. I was awake before seven, and Zack and I watched American Ninja Warrior while Grandma and Grandpa got dressed.
That day’s plan was to head toward Rincón.
We had already spent several days exploring Puerto Rico, including a Mother’s Day evening in La Parguera, and this day would take us farther along the island’s western coast.
We left around nine and drove through Aguadilla, enjoying beautiful views of the beaches from the mountains along the way.
Eventually, we stopped near a beach famous for surfing competitions.
And there, near this beautiful stretch of Puerto Rican coastline, was something I certainly hadn’t expected to see:
A massive concrete dome associated with a nuclear reactor.
I took some pictures.
I asked enough questions to come away with a basic explanation.
And then I wrote this in my journal:
“We also saw a nuclear dome that was built but never used. They spent a ton of money to build it and then the people in the surrounding community didn’t want it near them so it was never opened.”
There was only one problem.
That isn’t what happened.
The Nuclear Reactor That Actually Did Operate
The strange structure we saw was part of the BONUS reactor facility.
BONUS stood for Boiling Nuclear Superheater, and the facility represented an ambitious experiment in the early development of nuclear power.
Construction began in 1960 through a partnership between the U.S. Atomic Energy Commission and the Puerto Rico Water Resources Authority.
This was during an era when nuclear technology wasn’t being envisioned solely as a weapon of the Cold War. Following President Dwight D. Eisenhower’s 1953 “Atoms for Peace” speech, peaceful applications of atomic energy became part of a much larger vision for the future.
Nuclear power promised progress.
Innovation.
Potentially cheaper and more efficient electricity.
And Puerto Rico became part of that experiment.
BONUS wasn’t simply designed to produce nuclear power using an already established system. It was an experimental reactor intended to test whether steam could be superheated inside the reactor core itself, potentially improving the efficiency and economics of nuclear-generated electricity.
This strange dome beside the Caribbean wasn’t just a power plant.
It was a laboratory for the future.
Puerto Rico Enters the Atomic Age
And despite what I confidently wrote in my journal in 2016, BONUS was not built and abandoned before it could ever operate.
It went critical—the term used when a nuclear reactor achieves a sustained chain reaction—on April 13, 1964.
By September 1965, it had reached full power.
For several years, the dome I casually photographed in Rincón housed an operating experimental nuclear reactor.
BONUS also held a significant place in the history of nuclear power in the region as the first nuclear power plant in Latin America.
Scientists and engineers were testing technology here that they hoped might influence the future of nuclear energy.
All of which makes my 2016 reaction even funnier in hindsight.
Huh. Nuclear dome.
Anyway, lighthouse.
When the Experiment Ended
BONUS was experimental technology, however, and experiments don’t always produce the results their creators hope for.
Technical problems developed with the reactor, and eventually the modifications required to continue operating it could no longer be economically justified.
In June 1968, BONUS was permanently shut down.
Puerto Rico’s nuclear experiment had lasted only a few years.
Decommissioning followed.
From 1969 into 1970, the nuclear fuel and other highly radioactive components were removed from the facility and shipped away.
But some components couldn’t simply be hauled off.
The reactor vessel and associated equipment were eventually entombed using concrete and grout, leaving behind the enormous containment structure that remains one of the area’s most recognizable landmarks.
From Nuclear Experiment to Domes Beach
Perhaps the strangest part of this story is what happened around the old reactor.
Life continued.
The experiment ended, but the ocean certainly didn’t.
The waves kept rolling toward Puerto Rico’s western shore, and surfers kept coming to ride them.
Over time, the unmistakable nuclear containment dome became so much a part of the surrounding landscape that the nearby surfing area became known as Domes Beach.
I love the contradiction of that scene.
On one side is the Caribbean: moving, crashing, endlessly changing.
On the other stands a massive concrete relic of the atomic age.
One was created by nature.
The other came from a particular moment in human history when we were trying to harness one of nature’s most powerful forces.
Today they simply share the landscape.
That meeting of human history and Puerto Rico’s extraordinary coastal landscape reminded me of another stop from this trip: the Cabo Rojo Salt Flats, where centuries of human activity have also become inseparable from the landscape surrounding them.
Is the BONUS Reactor Abandoned?
Calling BONUS an “abandoned nuclear reactor” makes for a wonderfully dramatic description, but it isn’t quite accurate.
The reactor was decommissioned and entombed, and the former facility remains under long-term oversight.
Additional cleanup and shielding work occurred decades after the original shutdown, and the U.S. Department of Energy’s Office of Legacy Management continues monitoring and inspections of the site.
So this isn’t a forgotten nuclear facility that everyone simply walked away from.
The experiment may have ended in 1968, but managing its legacy became part of the story too.
And that’s an important distinction—especially when we’re talking about nuclear history.
What I Actually Saw in 2016
Here’s where this story becomes particularly personal for me.
I didn’t explore BONUS.
I didn’t tour the facility.
I didn’t walk through abandoned control rooms or stand inside the containment dome.
I simply saw it from the nearby Rincón beach area.
I took a few photographs.
I learned a tiny—and apparently inaccurate—piece of its history.
Then we moved on.
Our next destination was the Rincón Lighthouse, where we couldn’t go inside but found a beautiful walkway with fantastic views over the ocean.
That stop became another story of its own, from Rincón’s famous surfing coastline to the lighthouse overlooking the Caribbean—and, of course, the giant iguanas we met along the way. You can continue our day in my story about Rincón Beach & Lighthouse.
We also encountered three enormous iguanas up close.
So, from my perspective at the time, the day was basically:
Beautiful drive.
Surfing beach.
Nuclear dome.
Lighthouse.
GIANT IGUANAS.
Puerto Rico was apparently determined to keep things interesting.
The History I Didn’t Know I Was Photographing
Years later, those few photographs mean something entirely different to me.
I wasn’t looking at some enormously expensive project that had been abandoned before anyone ever switched it on.
I was looking at the remains of an actual chapter in the history of nuclear energy.
People worked there.
Scientists experimented there.
Engineers tried to solve problems there.
For a brief period in the 1960s, people looked toward this corner of Puerto Rico and wondered whether the technology being tested there might help shape the future.
Then the experiment ended.
And eventually the extraordinary became ordinary.
The nuclear dome became part of the scenery.
Surfers caught waves beneath it.
Travelers like me took pictures of it.
Some of us apparently wandered away without understanding much of anything about what we’d just seen.
What Stayed With Me
This is exactly why I’ve grown to love creating TMP Origins.
These aren’t trips I took as a travel-history creator.
I wasn’t researching every stop beforehand or standing there thinking about how I would eventually tell its story.
I was simply traveling.
Sometimes I understood what I was seeing.
Sometimes I didn’t.
And sometimes—as BONUS proved rather spectacularly—I thought I understood and was completely wrong.
But the trip doesn’t necessarily end when you come home.
An old photograph can become an invitation to go back.
A forgotten journal entry can raise a question.
And a strange concrete dome sitting in the background can suddenly open a doorway into the Cold War, the atomic age, and Puerto Rico’s place in the history of nuclear energy.
That’s what happened here.
In 2016, I saw a nuclear dome beside a beach.
Nearly ten years later, I finally discovered its story.
And maybe that’s one of the best things travel leaves us with:
Not only memories of what we understood while we were there, but mysteries waiting for us to come back and look again.
Watch the Full Story
Want to see the photographs that started this rabbit hole and hear the full story of Puerto Rico’s BONUS reactor?
Watch I Almost Overlooked Puerto Rico’s Nuclear Reactor on Travel Made Personal.
And while you’re there, come explore the rest of my 2016 Puerto Rico journey through TMP Origins, where I’m returning to the places in my old travel journals and discovering the history I didn’t know I was standing in.
Because every place has a story…
even the ones you almost missed.
Some travel stories don’t reveal themselves until years later.
Join the Travel Made Personal mailing list for stories from the road, forgotten history, behind-the-scenes adventures, and the unexpected discoveries I find when I go back and look again.
Because sometimes that weird thing you photographed on vacation turns out to be a Cold War nuclear reactor. 😂
Come see what else we almost missed.
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