Surprise!

At a beach house on the south shore of Long Island…

Pretty normal asphalt shingles, in a photo taken from a terrible angle

But interior removal of the ceiling showed that the original roof was wood shingles, installed in the traditional manner over battens, without a solid roof deck, and still present:

The lack of recent water damage or staining – and the cobwebs – suggest that the asphalt shingles are doing their job. Which is good, because reroofing would mean nailing new roofing to the flimsy wood shingles and battens, nailing through the flimsy wood shingles and battens to the rafters, or removing the shingles and battens and installing a plywood deck. Each option is tiresome, in its own way.