I sometimes like to think of the pavement as a roof â€“ the roof of the busy underground world that supports our day-to-day living. And if the pavement is a roof, then manholes (correct term:Â maintenance holes) are skylights, and service covers are the shutters on those skylights. I wrote earlier about how I tried to peer down a chink in one of these â€˜shuttersâ€™ to see the Paris sewer system below. How gauche can a tourist get?
Geoff Manaugh makes a good suggestion on his BLDGBLG site: how about installing â€˜upside-down periscopesâ€™? In vertically dense cities, he proposes, these would allow everyone to peer down into subterranean infrastructure, exploring subways, cellars, plague pits, crypts, sewers, buried rivers and streams. They would be a kind of archaeological â€˜truth windowâ€™.