I'm sure the stairs are part of the footpath.
Here's what I could find in Google image search. It's on Ulleunggo Volcano 75 miles off the coast of South Korea. I haven't located another pic of the staircase as I'm having difficulty pinpointing where exactly it is. Google Earth shows the lighthouse in the middle of town
Here is the person who took the photo.
The Spiral Staircase
Photographer’s Note
A very unusual part of the walkway, leading from the lighthouse, to Jeodong town, along the cliffs of this rocky volcanic shore, where the terrain plunges straight down into the sea. From memory, I think the stairs are 57 metres.
Ulleunggo Volcano is about 75 miles off the east coast of South Korea, & last erupted over 9,350 years ago, with a force equivalent to Pinatubo, in the Philippines, in 1991.
It's a very interesting place I'm glad I checked it out
Exploring Ulleungdo Island: A volcanic island formed by wind & fire - Recommended Hiking