I first read this book as a teenager many, many years ago. There was a lot I identified with - growing up in a seaside town in the 70s, the feeling of never quite fitting in - and ever since reading Narnia I've been searching for that other world, somewhere beyond the horizon.
Although there are a few rough edges (character POVs that suddenly leap from one to the other) I was delighted to find this on Kindle and read it again. It still conjures the same magic and atmosphere, with terrific descriptions of the hidden caves, the mists, the marshes and the secret city of Brancaer, contrasted with a sweltering summer on the south coast. I loved it.