Book excerpt: The Channel Tunnel has been called the greatest engineering project of the century, overcoming a unique set of financial, political and engineering challenges. This book provides a comprehensive insight into the events which culminated in the first dry link between Britain and France. It describes the relationship between the site investigation, data interpretation and construction of the works. It examines areas such as the difficulties inherent in predicting geology from a relatively small number of boreholes and revealing how the use of modern geophysical techniques.