After two gloriously hot days camping on the beach in Arhus, we awoke to rain pattering on our tent, and knew today was not a day for swimming. We had already seen the pretty Gamle By (Old Town), a collection of historic buildings moved into a village setting from all over Denmark and Arhus’ main tourist attraction. The tourist info centre pointed us to Randers Regnskov, a short but luxurious train ride away.

Randers Regnskov (rainforest) is a cross between the Eden Project and a specialist zoo. It aims to be self-sustaining, with an ecosystem of over 200 animals and 450 plants all forming a food chain and playing their part in regulating the sealed environment. The day we visited, it was 28 degrees inside, with 90% humidity – reminiscent of the Amazon.

The glass domes of the project house a tropical garden complete with waterfalls, ficus trees and huge ravenala palms. I was impressed by the clever design of the terrain that allowed large caimans and small deer to coexist outside cages without ever crossing paths. A roaming guide told me that, after lots of experimentation, they were close to their self-sustaining goals, and only had to add butterflies on a regular basis. They had recently increased their beetle population to take care of the excess dung, and now have no need to clean up after the larger animals, or to fertilise the plants.

There are some barriers so, for example, the otters don’t decimate the fish population, but as a rule it’s a spectacularly naturalistic experience. I was thrilled by the butterflies, bats and macaws flying right past my face and – just like in a real forest – the way that a huge iguana would suddenly become visible, having been sitting two feet away the whole time!

It’s not for everyone, but I was keen to see the snake room, which is separated to protect the rodents and birds. Some people seemed to be daring each other to stride quickly through the enclosure of 20 non-venomous snakes, and I saw one woman manically flapping her hands around to swat away any potential threats. Poor snakes! They largely hid in the trees, obviously feeling somewhat harassed.

Randers is an otherwise unremarkable little town, but the Regnskov is well worth the side trip from Arhus. It’s a fun day out but is also becoming an important research centre for botanists and biologists who can set up ‘real world’ experiments without travelling to South America. As an education centre it beats any zoo I’ve seen, because it demonstrates the interdependence of species and the value of the humble beetle or butterfly.

It is also, of course, just beautiful.