The great Outer Beach described by Thoreau in the 1800s is protected within the national seashore. Forty miles of pristine sandy beach, marshes, ponds, and uplands support diverse species. Lighthouses, cultural landscapes, and wild cranberry bogs offer a glimpse of Cape Cod's past and continuing ways of life. Swimming beaches and walking and biking trails beckon today's visitors. Cape Cod's weather is generally moderated by its proximity to the ocean. Winter is typically cold with some snow. Spring is often rainy. Summer is usually warm and humid. Fall is generally dry and clear.