The first batch of four sets were produced in 1970 for BSB, with Letraset following their usual path & releasing them subsequently in an English edition. Another batch of four followed in 1972, & a final round in 1976 to complete the set of twelve. The cover designs changed with each batch, so you can easily tell which titles belong to which batch, even if you can't read the number on the front panel.
The first batch in particular have a very Germanic feel, which is easy to understand when you read the text on the back cover:
"Devised by Inge Ballhausen, illustrated by Detlev Richter.
©1970 BSB-Aktiengessellschaft fur Mechanische Beschriftung und Dekoration — CH 4000 Basel."
It will be the English versions which are covered here, although you can see a glimpse of one of the German-language originals, on the page for No.4: "Down on the Farm".
Since eight of the twelve titles scrupulously adhere to the "World in…" format, the entire range makes for an interesting set of variations on the theme of World maps.
The series as a whole is interestingly different from most other Action Transfers, & of an impressive standard — also including a couple of surprises.
This panel (from the back of No.10) demonstrates Letraset's own take on the situation:
The Twelve World in Action Transfers Sets:
No.1:
Famous Voyages of Discovery
No.2:
Famous Buildings of Europe
No.3:
Animals of the World
No.4:
Down on the Farm
No.5:
Aircraft of the World
No.6:
Robinson Crusoe
No.7:
The American Indians
No.8:
Wonders of the World
No.9:
Birds of the World
No.10:
World Travel
No.11:
Children of the World
No.12:
Marine Life of the World
• Get Started with No.1: Famous Voyages of Discovery →
• The Action Transfers Page: →
• The Super Action Transfers Page: →