← Back to the trip map
Amsterdam · Curiosities

Amsterdam curiosities & wonders.

A joyful grab-bag of true, delightful, faintly improbable things about Amsterdam — a floating home for rescue cats, thousands of bikes hauled from the canals every year, a whole church hidden in an attic, houses that lean like they're dancing, and three X's that mean nothing you think they do.

catboat15,000 bikeshidden churchskinny housesleaning gables1,500 bridgeshouseboatsXXX
TL;DR — Amsterdam runs on water, bikes, and quiet cleverness — and it hides its best wonders in plain sight: an attic, a courtyard, a one-metre facade, a boatful of cats. Go looking for them.
Related: Amsterdam field guide → The Amsterdam stop & itinerary → Trip map →
Bikes dredged / year
12–15k

Bicycles fished out of the canals every year by a barge with a claw.

Cats afloat
~50

Rescue cats housed at De Poezenboot, the world's only floating cat sanctuary.

Bridges
1,500

Crossings stitching the canals together (counts range 1,200–1,500+).

Narrowest facade
~1 m

The rear wall of Singel 7 — about the width of a doorway.

Twelve small wonders

All verified — and where a beloved factoid turns out to be a myth or a maybe, it's flagged honestly in the card. Wander these on foot; most are a short canal apart.

🐱 A boat full of rescue cats

In 1966 a woman named Henriette van Weelde found a cat and her kittens under a tree by the canal and took them in. She kept taking in strays until, in 1968, the colony got its own barge. Today De Poezenboot — moored on the Singel — is the world's only floating cat sanctuary, home to up to ~50 rescues (about 14 permanent residents), and it's free to visit.

🚲 12,000–15,000 bikes fished out a year

Every year the water utility Waternet sends a barge with a hydraulic claw along the canal bottoms and hauls up between 12,000 and 15,000 bicycles — a feat once recognized by Guinness World Records. Most got there through theft, vandalism, or a very good night out. They're sold for scrap or repaired.

🚲 More bikes than people

Roughly 850,000 Amsterdammers own an estimated 880,000+ bikes — some counts run past a million. Nobody can count them exactly, so the city's statisticians literally use the "Wisdom of the Crowd": average a panel of expert guesses and call it the truth.

⛪ A whole church hidden in an attic

After 1578, Catholic mass was banned in public, so Catholics built secret churches out of sight. Behind an ordinary canal-house front on the Oudezijds Voorburgwal, the top three floors conceal a full 17th-century church — Ons' Lieve Heer op Solder ("Our Lord in the Attic," 1663) — pews, altar, organ and all. It's the second-oldest museum in the city.

📏 The narrowest houses (a tax dodge)

Amsterdammers were once taxed on the width of their canal frontage, so they built tall, deep, and skinny. Singel 7 has a rear facade barely a metre wide — though its front is normal-sized, so it's a bit of an illusion. The real title-holder over its whole length is Oude Hoogstraat 22 at about 2 metres — now home to the city's tiniest tea shop.

🪵 The oldest wooden house — age disputed

In the Begijnhof stands Het Houten Huys, one of only two timber-fronted houses left after fires led the city to ban wooden facades in the 1400s. Its plaque long claimed 1420 — but tree-ring dating in 2010 pushed the real date to around 1528. Ancient either way; just not quite as ancient as the legend.

🌿 A medieval courtyard hidden in plain sight

Slip through one small gate off the busy Spui and the city noise vanishes: the Begijnhof, a walled women's enclave dating to at least 1346, invisible from the streets around it. It was built for the béguines — devout women who lived communally without vows. The last one died in 1971; about 100 women still live there today.

✝️ The three X's are NOT what you think

The XXX all over Amsterdam are three St Andrew's crosses from the old coat of arms — nothing to do with sin, vice, or the Red Light District. And the much-loved story that they stand for the city's three historic scourges — flood, fire, plague — has no historical evidence. Historians think they came from a medieval lord's family shield.

🌉 1,500 bridges and a Skinny one

Amsterdam is stitched together by well over a thousand bridges (counts range from 1,200 to 1,500+). The most beloved is the Magere Brug — the white wooden "Skinny Bridge" over the Amstel, officially bridge no. 242, strung with about 1,200 light bulbs that glow gold after dark.

💃 The houses that lean and "dance"

Many canal houses tilt forward on purpose — "op vlucht" — so goods hoisted by the roof-beam clear the facade, and so tall fronts don't look like they're toppling backward. Add centuries of wooden foundation piles sinking into swampy peat, and you get the crooked, leaning "dancing houses" of the Damrak.

🏠 2,400 floating homes with real addresses

Those houseboats aren't scenery — they're legal residences, with mail, sewer hookups, and permits. Amsterdam recognized and regulated houseboat living in the 1970s and eventually capped legal moorings at around 2,400, so today a permit is a rare and coveted thing.

🎨 A canal-house museum devoted to cats

At the grand Golden Bend of the Herengracht, the KattenKabinet fills a 1667 mansion with six centuries of cat art — Rembrandt, Picasso, Toulouse-Lautrec. It was founded in 1990 by a financier in memory of his ginger tomcat, whom he had named, with a straight face, John Pierpont Morgan.

Kept honest: the "XXX = flood/fire/plague" story is a charming myth with no historical backing; Het Houten Huys is likely ~1528, not the fabled 1420; Singel 7's one-metre facade is only its rear wall; and the bridge count genuinely varies by source (1,200 to 1,500+). All still true and delightful — just told straight.

Where these come from