A bridge through a dark space, made of luminescent energy. The bridge is a simple flat rectangle, perfectly sturdy, about two meters wide. There are no rails or supports, and the bridge is so long, and the void it crosses so dark, that one cannot see one side from the other.
A huge, underground edifice. Encountered deep beneath the surface, after a long climb down. It is in a clearly ancient architectural style in an enormous subterranean chasm; it can be viewed from above from a ledge on the way down. Its size and design inspire awe and fear; surely no surface creature has ever been down here before. But then, who built it?
A long-abandoned island city, viewed from afar. The buildings are all ruined, the streets overgrown with weeds. No one has set foot here in ages. But despite the dereliction of the place, the green plants juxtaposed with half-standing towers leads one to think that the place could be rebuilt.
A room, deep in the insides of a massive starship, where all the walls look like the insides of a modern computer. Literally covered in microchips and circuitboards, this is the brain of the starship. To fix a malfunctioning component would require a ladder and a magnifying glass.
An anthill on a grass-covered highway median. The ants who live there have never ventured outside the median for generations upon generations, for they would surely be crushed by the high-speed traffic. The fact that there is even life outside their little grassy island is totally unknown to them.
A small sign on a streetcar, asking travelers to yield their seats to the elderly and infirm. The commuters see that sign every day. Their eyes gloss right over it. Someone spent an afternoon just deciding what font the lettering should be.
A basement corridor in an old building that’s since been put to better use. No one goes into the basement anymore except to access a few key rooms. No one ever goes into that corridor. It’s not that there’s anything wrong with it; there’s just no reason to.
A basement of a community center, with a closed door leading to a staircase down. The children play in this community center all the time, and sometimes activities are held in this basement, but they are told never to open that door. Some children have peeked, and know the stairs go down somewhere. But no one has ever gone down there.
A tiny pothole in a paved elementary school play yard. Every night, at midnight, the pothole changes shape. One day it’s a circle; the next a triangle; the next a square. It’s always slightly irregular, so one cannot be sure that it’s really changing. But it is.
A secret set of footholds along the edge of a royal palace. They lead down from the prince’s bedchamber to the royal woods beyond. No one but the prince knows they are there, but he did not make them. His great-great-great-great-great-great-great-great-grandfather did, when he was a boy.
A book in a big public library that no one has ever checked out. The book contains the rules to a game that’s long been out of print. The book was donated by a family whose two boys used the book to play a make-believe game. But they did not own the game, nor did they follow the rules properly.
A secret room, hidden away in a certain chain store. Step into the room, and the doors slide closed, revealing a map of all this store’s locations. Touch one of the other locations. The room vibrates for many seconds. Then it stops, the doors open. It looks like you’re in the same store. Until you leave the store, it’s hard to tell, but you’re actually in the location you selected.
A tiny island, a minuscule mound of land no more than 40 square meters in area. Nothing but ocean around it. The island is a little grass-covered hill, with a circular hole at the very top that’s maybe a meter wide. The hole seems to go down forever. The geographic coordinates of this island are 31.78° S, 144.77° W.
An old park bench. Once a old jogger with an undetected heart condition felt a pain in his arm, staggered over to the bench, sat down, and died. Another time a pair of young lovers sat next to each other on the bench, confessed their true feelings to each other, and kissed. Their initials are carved into the wood at the exact spot where the jogger’s head rested. It is an old bench. The city is thinking of replacing it.