Without question this massive primer on the Central Andes Art (an often forgotten cradle of civilization). It is A LOT of information in surprisingly digestible format, with TONS of mysteries to port wholesale. It starts you off with the major recurring cosmological underpinnings which gird you from Chavín to Inca and paint a truly fascinating world.
The topics of hallucinogenics as ritual cultural adhesion is properly jargonized into entheogenics, and similarly a level of respect is shown throughout all the arts on discussion. It also shows how trade is absolutely essential in a space where three of the harshest climates (coastal desert, tropical jungle, and high altitude mountains) share such a narrow band along the continent. And then the scale of art, cities, and complexity is given the jaw-dropping explanation they deserve to drive home the achievements made.
Bar none, easiest crash course on history, religion, politics, trade, & material culture through a breezy stroll down millennia of art -- in a tiny, tiny book! It also seeds wonders and mysteries ready to port into any campaign from fantasy to mythos investigator. Read it from the library and am kicking myself that this should be in my collection by now.
Happy travels for your kid!
Art of the Andes: From Chavín to Inca (World of Art)
Series: World of Art
Paperback: 248 pages
Publisher: Thames & Hudson; 3 edition (September 10, 2012)
Language: English
ISBN-10: 0500204152
ISBN-13: 978-0500204153
Product Dimensions: 6 x 0.7 x 8.3 inches
PS: This should help world building massively, but if you or your kid have any questions feel free to ask. The book does a better job, but if you wanna do something like use quipu (the accounting language of fabric knots) into a fully complex writing system that can have let's say: novels, I say go for it! (I'd assume "spellbooks" in quipu to be a given, personally.)