Scavenger Hunts · Self-guided walking adventure
The Secret of the Spanish Fortress
A stone in the Keeper’s notebook can hear the fort’s memories. To wake it, your crew must solve the questions of an apprentice engineer.
More than a walk. A story your family solves together.
Makes the fort make sense
Most kids see “a big old wall.” This hunt has them figure out why coquina absorbed cannonballs, why the corners are pointed and how the city survived a siege.
Pairs perfectly with a fort visit
Play outside before you buy fort tickets, and the inside will mean twice as much. Or play it on its own; no ticket is required.
Science, history and puzzles in one
Ciphers, a hands-on impact experiment and a treaty puzzle. It’s great for homeschoolers and kids who like to know how things work.
10 clues, one story
Start: An open exterior viewpoint of the Castillo de San Marcos
Finish: The same viewpoint
- The stone with a secret
- The shell cipher
- The missing start date
- The engineer chooses a corner
- The night the walls listened
- The impact experiment
- The treaty key
- The repeated test
- The people behind the wall
- Wake the listening stone
Plus 3 optional deeper missions: Two wars and a back door, Make the blind spot visible, Who built the protection.
“The stone with a secret…” Stand where you can see the fort’s walls and look for what they’re really made of. It isn’t what most visitors think.
What you get
- Opens instantly on your phone. No app to download.
- Clues one at a time, with a hint on every clue
- A “Grown-up: show answer” button so nobody gets stuck
- Progress saves automatically: stop for lunch, come back later
- A finger sketch pad and 3 bonus missions for curious kids
- A full story ending and the Shell Seal for your Detective Passport
- Every stop is outdoors and public, so no admission tickets needed
- One purchase covers your whole group on the same outing
Best time: Mornings, before the midday sun. Stay on open paths away from walls, drops and cannon equipment.
Tried our free walk? This is the full story.
| Three Keys free walk | Spanish Fortress | |
|---|---|---|
| Clues | 3 | 10 + 3 bonus missions |
| Time | About 20 minutes | 45–60 minutes |
| Story ending & passport seal | Gate Seal | Shell Seal + full ending |
| Hints & grown-up answers | Yes | Yes |
| Price | Free | $14.99 per group |
Good to know
Do we need to buy Castillo tickets?
No. Every clue is played from open exterior areas. If you want to go inside, buy entry from the National Park Service; the hunt makes a great warm-up.
How long does it take?
About 45–60 minutes, plus three optional deeper missions if your crew wants more.
Is it good for school or co-op groups?
Yes. It connects to Florida history, forces and materials, and one purchase covers your group on the same outing.
What happens after I buy?
Your adventure opens instantly on your phone in the browser. There’s no app to download. Save or bookmark the link, because it’s how you get back in.
How many people does one purchase cover?
Your whole group on the same outing: a family, a class, a co-op or friends. Share one phone or all follow along together.
All sales are final. Adventures are digital and unlock instantly. Trouble opening yours? Email hello@since1565.com. Please play safely on public sidewalks; see our Terms. More answers in our Scavenger Hunt FAQ.
Pair it with another adventure, or something happening this week
Ages 6+ with an adult · $14.99The Lost Treasure of St. Augustine
See this adventure →
Ages 10+ with an adult · $19.99The Ghosts of the Ancient City
See this adventure →
EventsWhat’s on in St. Augustine
Festivals and events in the next 60 days →
Hungry after? See where to eat near the finish.