On December 30th, 2015, two of us set out for a New Years Eve trek along the Lost Coast. The ~25 mile trail hugs a remote shoreline on the Northern California coast. The northern trailhead at Matthole Beach takes some time to access via windy, rugged dirt roads, while the southern terminus at Black Sand Beach is more easily accessible. After dropping off a vehicle at the southern end, we drove up to Matthole Beach, and set off onto the trail.
Although almost the entire trail is flat - or as flat as it gets when backpacking - the terrain can be challenging at times, and it's constantly changing from a nice dirt path, to lesser nice sandy paths, to rock fields. There is one point on the trail where scrambling over giant rocks is required to pass. Another thing which must be observed are the tide charts, because there are two 4 mile portions of the trail which must be passed when the tide is low, otherwise one runs the risk of getting trapped in a dangerous position between the ocean and the cliffs. Last but not least, there are many stream crossings on this trail -- as many as one every mile or two during winter and spring. While some of the crossings are rather easy, there are a few that can be difficult -- hiking poles are definitely recommended on this trail for that reason! These streams all run directly into the raging ocean, of course, so you'll want to be able to cross the ones that are flowing with force with confidence!
Other than those obstacles, this trail is on the easier side as far as energy and endurance needed to complete it, and it provides amazing views of a pristine oceanfront wilderness.