What are gasholders and how do we mark engineering heritage when technology moves on? Professor Russell Thomas, Technical Director of WSP, and Timur Tatlioglu, Partner and Head of Montagu Evans’ Historic Environment and Townscape Team, discuss the past, present and future of these iconic structures. Russell and Timur are the editors of a new book, Gasholders: A History in Pictures, with the assistance of National Grid and Historic England.