1930s Big 15" Fold Out Book of the Zoo - Pictures of London Zoo

Printed in England in the 1930s this 3 part fold out Picture and Story Book entitled The Children's BOOK OF THE ZOO has 3 big pages of colourful illustrations of some animals found in zoos and their enclosures.
And on the other side - information, for children, about the zoo experience.
Based on London Zoo as one of the picture is of the Mappin Terraces built in
1913 -14 for bears. The construction of the terraces showed what could be done with reinforced concrete, which was then a comparatively new material.
In this picture there are polar bears on the terraces, now there are kangaroos and emus.
On the front of the book is the wonderful Penguin Pool finished in 1934.
The book is 15" tall and when folded out nearly 20" wide.
I found these in an old warehouse and they are in good condition  - just the odd dusty area on the covers.