In Nyckelviken Naturreservat you can find 2 hiking trails (yellow and blue), the blue one here is a bit more demanding than the yellow one and is 5.7km long. The route takes you through a variety of settings through the forest, on some of the rocky hills, along the beach and has some great viewpoints. If you like, there are also some picnic spots on the way. One of my favourite walks around Nacka that you can do in 1-2 hours.