Gwyl a Hwyl - Io, Gaiws!/Gwyliau'r Gaeaf

The fifth book in the Pen i Waered series. The story is about a slave called Gaius, during the Roman period. There's another book if you turn it upside down, which is full of colourful photographs and interesting facts about different holidays that are celebrated all over the world, such as Diwali and the Chinese new year.