What is the mysterious city of Machu Picchu?

Who built Machu Picchu, and why? Why was Machu Picchu abandoned? Who helped rediscover Machu Picchu? Have you started your FREE TRIAL of Who Smarted?+ for AD FREE listening, an EXTRA episode every week & bonus content? Sign up right in the Apple app, or directly at WhoSmarted.com and find out why more than 1,000 families are LOVING their subscription! Get official Who Smarted? Merch: tee-shirts, mugs, hoodies and more, at Who Smarted?