Hikers who enjoy identifying trees and plants can now keep an eye out for rocks, with the launch of a reader-friendly guide to geology. Twenty-four sites including early and middle Jurassic fluvial (river) deposits in Tai O are highlighted and described in simple Chinese. Detailed transport information is provided on how to get to the sites, along with maps and photographs. Field Trip Guide to the Geology of Hong Kong is published by the Geotechnical Engineering Office of the Civil Engineering and Development Department and costs HK$66. It is being touted as a useful source for travellers and hikers, and written in a way to interest the general public in the city's geology. Samuel Ng Kwok-choi, chief geotechnical engineer of the department and co-ordinator of the book, said: 'We specifically chose sites that can be accessed by public transport so that people who are interested would be able to visit them.' Dr Ng said he was inspired by memories of his studies in Canada, where he found various travel guides to provincial parks, listed with detailed transport suggestions. In Hong Kong, he had found little in the way of information or guidebooks. 'We have published many professional reports and information before with beautiful photographs and simple descriptions. It's good to introduce the sites, but it's also good to mention how to get there.' While there are numerous publications on the city's geological sites, Dr Ng said the guidebook is the first manual written with simplified observations in plain Chinese. 'Students, the public or tourists can easily understand the geological information in the book.'