The Eastham Conservation Foundation and Harwich Conservation Trust are co-sponsoring two guided walks in Eastham with historian Don Wilding on Saturday, May 15th. From 10 a.m. to noon, walk along the Nauset Marsh Trail and learn about historic storms, shipwrecks, and rescues. Then, from 1 to 3 p.m., learn about Henry Beston’s The Outermost House with a walk overlooking Nauset Marsh and “the Great Beach.” Registration is $20 at harwichconservationtrust.org.