Delfzijl — Secrets of the Ebbe
Uncover the cryptic secrets of the Ebbe, a hidden network of spies and smugglers operating from Delfzijl's historic bastions during WWII. Decipher clues at 8 landmarks to expose the final betrayal before it's lost forever.
📱 1 to 10 phones · 1 team per phone · Independent codes
In the shadowed canals and sturdy bastions of Delfzijl, the Ebbe was no mere tide—it was the codename for a daring underground resistance cell during World War II
Delfzijl — Secrets of the Ebbe
You are Klaas Annema, a 19th-century whale fisherman from Delfzijl, just returned from the Spitsberg ice.
Your mission is to decipher the secrets of
Dive into the maritime legends of Delfzijl, a port city in Groningen, where the history of tides and fortifications still whispers along the Eems.
The story that haunts this land
Your quest begins on the Havenkade, Delfzijl's main commercial port quay, 1.2 km long and built in 1870. It is here, along this 1.5 km stretch bordering the Eems dike, that you observe ferries departing for Emden, Germany, with up to 20 crossings per day. The port of Delfzijl, essential to Groningen's heritage, has always been a crossroads of trade and defense. As Klaas Annema, you recognize the currents and winds that guided your own expeditions to the Far North, imagining the merchant ships and warships that shaped the history of this gateway to the Wadden Sea.
Continue towards the Monument voor de Gevallenen, a 1940-1945 memorial inaugurated in 1949, an 8m granite obelisk erected on the dike. This site, located 700m from the start near the Stadhuis, commemorates the 105 names of resistance fighters executed or deported. It is a replica of the 1936 Peace Monument in The Hague. This place of remembrance reminds you of the sacrifices of those who defended the freedom of Delfzijl and the Netherlands, a history of resilience that resonates with the perpetual struggle of the inhabitants against the elements and invasions.
Your journey then takes you to the remains of Fort Lauenburg, a star-shaped fort built in 1594 by William Louis of Nassau to defend the Eems. Dismantled in 1672 after its capture by the French, its vestiges are visible near the port, 800m from Havenplein, integrated into Delfzijl's historical fortifications. These ancient walls are silent witnesses to the conflicts that shaped the Groningen region, highlighting Delfzijl's strategic importance as a defensive bastion against foreign powers and the tides of history.
Explore the Oude Haven, the old inner harbor dating from 1610, dug to protect merchant ships. 500m long, it has been connected to the Eemskanaal since 1825, and is 400m from Havenplein. It was the former base for whaling fishermen heading to Spitsberg in the 17th century, a period you, Klaas Annema, know well. It is here that Delfzijl's maritime soul truly comes alive, with memories of distant expeditions and the comings and goings of ships that enriched the city and marked its identity over the centuries.
Your adventure concludes at Delfzijl's Stadhuis, the neo-renaissance town hall built in 1918 by architect J. Koch. With its 35m tower and 1925 carillon bells playing maritime hymns, this building, 600m from Havenplein via the dike, features a facade adorned with nautical motifs. This building is a symbol of Delfzijl's pride and resilience, reflecting Groningen's maritime heritage. As Klaas Annema, you leave with the certainty that the secrets of the Ebbe and the city of Delfzijl continue to live on, inscribed in its monuments and waters, an interactive visit that has transcended time.
A game, a guided tour and a heritage guide — all in one
You're not just buying an escape game. You're carrying a living guide — historical anecdotes, forgotten legends, key monuments, hidden architecture — unfolding as you go.
At each stop, places ordinary guides miss — secret façades, sculpted crests, alleys steeped in history.
Every riddle is rooted in a real historical fact or local legend. You leave with dozens of stories to tell.
Learn to read buildings — flamboyant Gothic, Baroque, Art Deco — like a real art historian, while having fun.
Walk through the city like a novel's character — every alley becomes a stage, every square a theatre.
A voice walks with you at every step, tells the story of each place, reads clues, adds a cinematic feel.
Keep access to the guide & game for 1 year. Come back any time, share it with friends.
« You will not leave this city the way you entered it. »
How does it work?
Explore the city on foot solving puzzles based on real historical facts. No locked room — the city is your playground.
No app to download. Play directly from your browser. Guided step by step, at your own pace.
One purchase per phone is enough. Play with family, friends or as a couple — everyone participates.
Point your phone at the façade: a historical character appears and speaks to you in your language. Golden letters magically write themselves on the wall to reveal the puzzle answer.
Stuck? Progressive personalised hints. The character repeats the puzzle on demand — at your own pace.
French, English, German, Spanish, Italian + 27 other languages auto-translated by AI.
The game downloads to your phone on start. Once the "✓ Downloaded" indicator appears, everything works without data — narration, AR, GPS and puzzles. Perfect abroad without a data plan.
Want to go deeper?
Places tied to your adventure — optional entries, totally up to you · per person
The Route
8 stages through the city
The gameplay: AR, camera, hidden clues
At each stop, open your phone camera: an augmented reality character appears on the façade and speaks your language. Hunt the clue — it materializes as golden letters on the real wall or floats in front of you. When you find it, the phone vibrates, an AR chest opens and reveals your answer fragment. 8 stops, 8 clues to find with the camera, 1 final code.
The stops on your route are a surprise. You'll discover them one by one, guided by your phone, starting from the meeting point.
How does it work with a group?
One phone = one team. Pick the number at checkout (1 to 10).
Solo, or a group sharing the screen. One team, one code.
Family, couple, or 2-3 teams competing. Each phone has its own code and its own score.
Friends, bachelor/bachelorette, small office outing — each their own code, each plays at their own pace. Tiered pricing then €6 flat per phone from the 6th.
- ✓All codes are independent — play at the same time OR separately, each team advances at its own pace.
- ✓Leaderboard between your teams + global game leaderboard — each score appears in the public ranking.
- ✓More than 10 phones or need a personalized quest? Discover custom tours.
Ready to live this adventure?
Get my code · 12€No calendar booking. Code sent immediately by email.
🔒 Secure payment · Code in 5 min · Free cancellation
Practical info
Why this route?
Military Strategy
Decipher the maneuvers of the German occupation and the counter-strategies of the Resistance.
Clandestine Codes
Intercept and decrypt secret messages to thwart a major plot.
North Sea Bunkers
Explore the remnants of the Atlantic Wall and their buried secrets facing the coast.
In the shadow of the bunkers, freedom whispers.
A legacy of courage against the enemy.
9 features nobody else has
OddballTrip combines gamified play, augmented reality and AI. All our competitors deliver 1 or 2 of these angles. We deliver all 5.
AR treasure chest
A golden chest floats in front of the monument. Tap → opening animation → reveals a secret message.
AR narrator character
Point your phone at the façade: a knight, witch, monk, sailor, detective or ghost appears full-screen and speaks to you in your language with their dedicated ElevenLabs voice (each character has their own unique voice) — your living guide.
Magic golden letters
At the puzzle climax, golden letters magically write themselves on the real wall — that's the puzzle answer. An unforgettable visual effect.
Written + audio narration
Every puzzle available as text AND voice-over: read at your own pace or listen eyes-free while walking. Great in groups and for accessibility.
360° radar + vibration
A mini-radar shows the target even behind you, and the phone vibrates when you aim in the right direction.
Heritage storytelling
Every puzzle weaves in real historical facts (architecture, era, anecdotes). You learn by playing — like a gamified audioguide.
Progressive AI hints
3 levels of AI-generated help: vibe → where to look → answer format. You're never stuck.
AR selfie memento
At the end of the game, capture a selfie with OddballTrip banner + mascot, shareable on Instagram, TikTok.
Zero app to install
PWA technology: open the link, it plays in your browser. Same quality as an app, no App Store hassle.
Frequently asked questions
Q01Concretely, how does it unfold outdoors?
You arrive in Delfzijl, Groningen, open the link on your phone, the story starts. It's the modern outdoor escape game: audio narration, camera puzzles, final code unlocked as a team. No install. No need to book a time slot.
Q02Can we take a break mid-trail?
Of course. Stop at a café, have lunch, resume later: your progress is saved. Many players bake a meal break into the trail, especially with families.
Q03Is Delfzijl — Secrets of the Ebbe good for a hen / stag party?
Great fit: no costume required, the team really collaborates (it's not a linear path), and the final code earns you a souvenir photo. Pick a calm time slot — early afternoon usually.
Q04What happens if it rains in Delfzijl, Groningen?
The game is playable in light rain — just keep your phone under a hood. For heavy thunderstorms, your code stays valid, you can postpone to another day at no cost.
Avis des aventuriers
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Your turn to play
Dive into the maritime legends of Delfzijl, a port city in Groningen, where the history of tides and fortifications still whispers along the Eems.
1 purchase = 1 phone. Play several on the same device.
No calendar booking. Code sent immediately by email.
🔒Secure payment · Code in 5 min · Free cancellation
🪙+24 TripCoins granted with your booking
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