Once Upon a Castle

Once Upon a Castle

Castle Diaries ⚑

We Used an Antique French Wine Jug as a Volcano. Spring is Going Well.

A science party, a septic system, a homemade constellation crown, and everything else that

Kamille Longstreet's avatar
Kamille Longstreet
May 02, 2026
∙ Paid

Spring break arrived with the usual ambitious itinerary.

We were going to bake things. Learn new songs. Do projects. Have picnics every day. Go to a film, visit a restaurant, build something with our hands. The list was long and optimistic, like all school holiday lists are - drafted by people who have temporarily forgotten that life takes longer than expected and that two small children have their own opinions about how time should be spent.

We did about half of it. We’re not sad about this. Our son had a birthday this month, and if you’ve ever tried to plan a themed birthday party for kids while also living in rural France with a septic installation happening in your garden, you’ll understand where the picnic time went.

He wanted a science-themed party.

This is not as straightforward as it sounds. The party decoration universe - online shops, party supply websites, the entire industry of themed birthday infrastructure - operates on a fairly fixed menu of acceptable children’s interests. Dinosaurs. Unicorns. Princesses. Woodland creatures. Space. There are approximately forty-seven variations of space available at any given moment, in every color combination, at every price point, shipped to your door in three days.

Science is not on the menu.

Which is why we tried. “Hey, how about a space party? Rockets! Stars! The universe! It’s basically science!”

“No,” he said. “Science. Which can include space,” he added generously, “but is not just space.”

Drat! Almost had him.


The crown situation.

I had bought him a birthday crown from Etsy years ago - adjustable, beautiful, and something we kept because we (I) loved it and because I was certain it would still fit. He wore it every birthday. I loved that crown possibly more than he did.

This year he looked at it and something had shifted. He was older now. More mature, and refined. And apparently that comes with stronger opinions. He wanted a science crown instead.

I want to be clear that a science crown is not something that exists on Amazon.fr. I looked. It does not exist anywhere within reasonable shipping distance of rural France on less than two week’s notice.

So I made him one.

The crown stayed on the entire party. That’s how I know it was couture.

I found our most science-adjacent wrapping paper - constellations and planets, which is space-themed rather than strictly science-themed, but we were working with what we had. I cut seven A4-sized sheets with scissors, did some origami folding magic, glued it with one of the kids’ school gluesticks, and held my breath.

It was actually quite good. He wore it for the entire party (voluntarily).

I’m choosing to count this as one of my finer achievements. (Watch me make it here - it took about fifteen minutes and was relatively easy on the crafting scale.)


The septic situation.

One week before the party, we received a phone call from the septic company.

Not a “when would work for you?” phone call. A “we are coming Tuesday” phone call. Two days before the party. We had been trying to schedule this for months - the coach house septic had to be installed in the kitchen garden area, which meant we couldn’t start any garden work until it was done, which meant the whole spring planting timeline was sitting behind it like a very patient queue. We couldn’t say no.

They came. They dug. A large excavator appeared in what was supposed to be our kitchen garden. Trenches opened up across the grounds. A substantial septic tank materialized in the landscape.

Nothing says ‘spring’ like trenches. (Romance is alive and well.)

We thought briefly about a septic-themed party. We could give the children test tubes and hard hats and have them analyze the bacteria in our drainage. Very science-adjacent. Very on theme.

We decided against this.

The excavation was finished two days before the party and it looked, I want to be honest here, quite ‘industrial.’ Dirt everywhere. Large tubes. A construction zone aesthetic that was not exactly what we had envisioned for a child’s birthday party at a French château.

We told ourselves the children would be looking up at the beautiful property rather than down at the torn earth. This turned out to be correct, mostly because we gave them a treasure map and sent them into the forest.

If you’re new here, I’m an American writer living in a small château in rural France with my husband Sean and our two children. Once Upon a Castle is where I document the renovation, the life, and everything France keeps teaching us. Paid subscribers get Castle Diaries, where I write the real version in real time. Come stay a while.

The party.

Some people have a bounce house. We had a controlled reaction and a centuries-old backdrop.

Sean, who is absolutely science-minded in a way I am not, was enthusiastic about the theme from the start. His vision: a treasure hunt, molecular structure building, a volcanic eruption, lab coats, safety glasses. All of it. For six-year-olds.

We procrastinated, as one does, and assembled the actual plan the night before.

Here is what we made:

A list of objects to find, with each child’s name written on the back in invisible ink. We provided black light pens. The children had to find their own name before the map was revealed - which meant they each held their paper up to the light with the focused intensity of tiny detectives, which was probably one of the best moments of the whole day.

The map itself was something else. Sean took an overhead photograph of the property, turned it into a hand-drawn illustration, and then we brought it into Canva to mark the locations of the hidden objects. Then - and this is where we became ‘those parents’ - we printed it, soaked it in tea water until the paper darkened and crinkled, glued beautiful wrapping paper to the back, and Sean burned the edges with a lighter.

We made a treasure map like responsible adults: tea-soaked, fire-kissed, and printed at the last possible moment.

It looked like something you’d find in an old chest in a château attic. Which, given where we live, felt appropriate.

The objects the children were hunting: small handmade atoms - oxygen, hydrogen, carbon, sodium - which our own kids had spent the previous day coloring and decorating. They were scattered around the property. The kids also needed to find molecular structure diagrams and connecting sticks, which would allow them to actually build the molecular models of vinegar (well, the acetic acid in vinegar 🤓) and baking soda once everything was assembled.

The hunt went well, mostly.

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