From a Roman ruin in the basement of a Waterstone's bookshop to Liverpool's other cavern club; from secret supper-clubs to a museum of baked beans; derelict factories and forest raves to the naturist club where Michael Winner directed his 60s nudie films, there are hundreds of hidden gems waiting to be discovered, all with a story to tell.

You might think you know the UK inside out. Maybe you can reel off the world-renowned museums, the best theme-parks, most popular restaurants, top 10 nightclubs, the must-see beaches. There are many wonderful and famous sites to see and of course they're worth a visit. But there's another layer of places that don't get the same attention that are equally amazing, if not more so. Hidden around every corner are neglected or forgotten sites that only locals, experts or anoraks know and care about.

With our team of Secret Britain detectives, we have delved into the undergrowth to bring a selection of the best, starting in tomorrow's Guardian and concluding in Sunday's Observer. But we urge you to get searching and find your own. And when you do, please don't keep them to yourself, share your secrets with us by posting them here.