Mannequins are generally bought, used once for a project, and then thrown away to landfill. Except here, at Mannakin in Lincolnshire. Thanks to Roz and the team at Manakin. My first thought was "don't those mannequins rot, just sitting out there in the weather?" And then I realised: no, not really, they're fibreglass. That's part of the problem Manakin's trying to help with!

The International Cocoa Quarantine Centre, at the University of Reading, has an important job: stop pests and viruses from hitching a ride, as researchers try to breed better and hardier varieties of cocoa. Here's how thev do it.

Hutton's Unconformity, at Siccar Point, is about an hour east of Edinburgh, in Scotland, and I've wanted to set my own two feet on it for years. And from it, I've got a bigger question: is there anything we've missed?

The Hill House, in Helensburgh, Scotland was decades ahead of its time... but that means it's also experimental. And damp.

Rochester, in the south-east of England, was a city for nearly 800 years. And then, in 1998, an administrative error took that city status away, likely forever. Here's the story.

In Fife, in the south-east of Scotland, there's the Elie Chain Walk: a footpath that's got a reputation for being dangerous. It isn't — as long as you're prepared, and as long as you watch out for the tide.

"Anderson's Piano" is a set of wires and signals at the Pass of Brander, near Falls of Cruachan in Scotland, that try to detect when there might be a boulder on the track. They're 140 years old, and so far no-one's been able to find a better solution — but they're working on it.

Deepstore doesn't let many people film in their massive facilities. So when the team at Laura Ashley invited me down into the mine to look at their archives, I jumped at the chance

"Daly's Bridge", in Cork, Ireland, is better known as the Shakey Bridge. Because it shakes. But what happens when a bridge like that has to be repaired and refurbished?

The Monte Toboggans, in Funchal on the island of Madeira, are wicker sofas: a bit like the gondolas of Venice, only you're going downhill in regular traffic.

Funchal Airport, on the island of Madeira, was too short for modern commercial airliners: but there was nowhere to extend to. The solution is one of the greatest civil engineering projects of our time.

The Chauvet cave, in the south of France, is one of the most important archaeological sites in the world, filled with art that's tens of millennia old. No-one's allowed in, for very good reasons: but just a few kilometres away, there's a near-exact copy. Is that enough?

Les machines de l'île, in Nantes, are famous for their giant mechanical elephant. And to my surprise, tourists can just pay and ride it.

The Wasserspiele of Bergpark Wilhelmshöhe are 300 years old, powered entirely by gravity, and entertaining tourists. As legacies for rich people go, there are far worse ones.

Monte Kaolino, in Bavaria, Germany, is 35 million tonnes of quartz sand, piled up over the years from a nearby kaolin mine. In the 1960s, one guy just turned up with skis, and now half a century later it's a theme-park destination for sandboarders and skiiers.

In Soda Springs, Idaho, there's a geyser that fires carbonated water into the air, on the hour, every hour. I paid a visit.

On Lake Geneva, Wisconsin, there's a summer tradition: "mail jumping". It's a bit dangerous, a bit ridiculous, and would never be allowed to start today. But it's a tradition.

The Roval Albert Hall is 150 years old; the roof is 600 tonnes of glass and steel. And it turns out that there's a terrifying technicians' trampoline, acoustic-dampening mushrooms, and a complete lack of connections.

The treadwheel crane, or treadmill crane, sounds like something from Astérix or the Flintstones. But at Guédelon in France, not only do they have one: they're using it to help build their brand new castle.

The Doppelmayr Garaventa Monorack is a decades-old product. I've no idea how I missed it before. But for the third video in the Monorail Trilogy, this isn't an advert: I'm just happy to be proved wrong.

At the Swiss Military Museum in Full, there's the last remaining example of a 1970s tank-driving simulator. But there's no virtual worlds here: it's connected to a real camera and a real miniature model.

The Udbyhoj Cable Ferry across Randers Fjord in Denmark is electric-powered: but rather than batteries, it's plugged into mains electricitv. Here's how it works.

Surely water simulation can be done with computers now? Well, not quite. At the University of Sherbrooke, there's an artificial research river, and I asked them to start it up.

The Montreal Olympic Sports Centre has a 20m (65ft) diving board. That's twice the Olympic height. Why would anyone need that?

The Bay of Fundy has cheap, clean power: if you can harness it.

TRIUM's Rabbit Line, on the University of British Columbia campus, sends slightly radioactive material under the streets of Vancouver at 100km/h (60mph). Here's how and why.