Manhole cover is never a popular discussion topic. Neither can it be easily associated with cultural conservation. Yet these essential public facilities do not only witness the changes of public works, but also reflect the development of the iron foundry industry of Hong Kong for the past century through different designs, materials and manufacturing techniques. The Conservancy Association Centre for Heritage (CACHe) organises this “Manhole Covers” exhibition in hope of unearthing the secret information hidden in the manhole covers, so as to attain better knowledge of iron foundries of our city, its craftsmen and operatives, to exhibit the birth of a manhole cover, and to explore the history of Hong Kong’s progressive public works. Through these most common covers, we present you the least explored territory of Hong Kong’s history.