Some of the highest dunes on the Cape and a clothing-optional stretch.. In Short This wide and isolated beach sits beneath some of the highest dunes on the National Seashore--late in the afternoon you won't have to worry about shade. The beach is popular with the duds-doffing crowd and a section of it is, unofficially, clothing-optional. From the small parking lot, head down the vertiginous dune and walk south for about five minutes to Naked City.