Thousands of Brent geese arrive at Castle Espie on the shores of Strangford Lough in one of the biggest natural spectacles of the year. Anna Ashdown, the warden there, explains how to recognise their calls, and how to tell them from other geese. And Helen Mark visits the Green Lane museum in the Roe Valley Country Park near Limavady. It's a place with many stories of the landscape, the people and a rich linen-industry heritage. But it was under threat of closure until a local heritage group stepped in. Helen meets volunteers, and also the park's first ever warden Danny O'Kane who set up the park some 40 years ago, and even saved the very building the museum is housed in Presented by Helen Mark. Listen again to the whole programme at BBC Sounds.