They belonged to another era, with vivid covers depicting brave British chaps fending off savage tribes or seducing exotic maidens.
The covers were much adorned, with anatomical additions and crude speech bubbles, by boys who’d probably never read the words inside, let alone wondered what the real Costa Rica was like.
However those books might have shown it, today’s Costa Rica, a tiny country linking two continents and two oceans, is one of the most forward-thinking nations on the planet.
Writer Gaia Vince has decamped there (from Catford), with her husband and two young children, for reasons of science, adventure and curiosity.
It’s a place that feeds just that, naturally, thickly covered in cloud forest and hosting a huge proportion of the world’s species within a tiny morsel of territory.
Yet what’s remarkable about Costa Rica is not so much the flora and fauna as the way humans have deliberately changed their attitude to them.
A few decades ago the nation was one of the most deforested on earth, its wildlife being driven to extinction on the back of a lumber lorry.
In a meeting with Costa Rica’s El Presidente himself, Luis Guillermo Solís, Gaia discovered that the roots of the change stretched back to 1948, the end of the last civil war.
Costa Rica abolished its army at that point, a message to every mother that her sons would never go into battle.
Gaia discovered that the roots of the change stretched back to 1948
Instead, Costa Ricans have focused on building a nation with a future, a future as much open to the sloths and the moths, the caterpillars and crocodiles.
To care for the environment has become a new kind of patriotism (surely the best kind going) and you could see the pride in the way people showed Gaia and her family the wonders of the forests and the coasts.
It was an added point of honour to have been part of the change.
Men were pleased to say that they had previously lived by hunting, that their fathers had sold chainsaws.
There was a touch of born-again everywhere, from presidential palace to deepest jungle, but a conversion focused on saving the planet not souls. Let’s pray the Gospel spreads.