Put on a sturdy pair of shoes, grab a waterproof jacket (just in case), and head for Musselburgh in East Lothian. And don’t forget to bring a wax crayon and some paper.Use the online map (or download a printable copy) to locate six illustrated plaques, hidden along the scenic 4km trail that follows the River Esk. When you find a plaque, make a rubbing with your crayon and paper.Use the online guide on the website to discover more about the wildlife and history of the area. And keep your eyes peeled for interesting plants, birds, animals and landmarks.Once you’ve discovered all six plaques, lay your rubbings side-by-side to reveal a secret 10-word phrase. Type the phrase at the website to unlock your special certificate.