In Harbin, the coldest major city in China's northeastern Heilongjiang Province, workers have been busy constructing a magical theme park known as "Harbin Ice and Snow World." Every winter, this park transforms into a dazzling wonderland of ice sculptures and structures, temples, castles and icy slides stretching up to 500 meters long. The giant ice blocks used in the construction mostly come from an ice stock carved straight from the Songhua River.