Arroyo Hondo Old Hwy 101 Bridge 

It was built in 1918 with elegantly curving arches under a two-lane highway. Built of concrete, it is now a popular pedestrian bridge. If you're looking for a daytime hiking adventure, find the unmarked trailhead on the west side of the bridge. At the beginning of the bridge you'll turn left to find a small path. The dirt trail will become a steep staircase (be cautious!) which will take you down to creek. Carefully find your way through boulders and driftwood to find the beach. At that point you can go either way but it's recommended to go right to explore the western coastline toward Gaviota State Park. Take lots of pictures and enjoy!