Well, someone I once wryly told could take 400 words to get through a door has free license to laugh and mock, because I have taken more than 500 words to deal with a sidewalk.
…It’s a very distinctive sidewalk. 😉
No, seriously, it is.
Fort Jefferson down in the Dry Tortugas was built using this stuff, and it’s still in amazingly good shape today. I figured some very old sidewalks in a fictional port town might well have used it. Besides, Late Silurian dolostone – tell me rock from the age of sea scorpions doesn’t fit a fantasy with a Lovecraftian bent. Not to mention the millipedes, crinoids, and tentaculitoids.
(Just the name on that last one….)
And the details involved in this particular sidewalk are important, because it’s one main character’s second-to-last Big Clue that lets them finally figure out a big piece of something seriously wrong in the whole mess. Not to do with the villain, but with one of the hero’s allies.
That sidewalk is going to lead to some painful honesty, and our poor apprentice detective realizing that a whole bunch of people have been misreading what they’re dealing with.
Of course, later he’ll find out things are even stranger than he thought… but one reveal at a time. 😉