This is a playful search-and-find book of underground systems around the world. Die cut pages introduce the subways of 10 different cities. On the first page we see the exterior of the train, and are presented with fascinating facts and figures about the transport system. On the following die cut page, we find the inside of the train and the platform, bustling with activity. On this busy page, young readers are invited to spot key items that are unique to the city in question; a pretzel, an I * NY t-shirt and a Statue of Liberty headband on the New York subway, for example. Perfect for train-obsessed children, but also for a wider audience, this book teaches young readers about transport and also about cultural signifiers of different cities around the world. Uijung Kim's busy, colourful illustrations have a manga-like sensibility that feels joyously contemporary.