and the slaterunners! rooftop-dwelling bands of half-bandits, half-free spirits - eva roadshun, alfred stayhigh, jonas ridgetrotter, marlene chimneyvault....led by inessa badladder (third generation groundless - i don't understand how you groundlubbers can live down there, walled in. my mother never touched down, nor my grandmother.)

and the unlondon moon - the loon - a perfectly symmetrical luminous spindle shape.

and the enormous november tree:

"fireworks were obsolete the instant after they ignited. every november on fireworks night the most choice effects of the most impressive displays in london would seep through into unlondon as they became moil (mildly obsolete in london) and blossomed into the november tree. over the year the tree would dim, shedding its glow and colours, until by november the fourth it was little more than a skeleton of smoke trails."

and tall buildings like chests of drawers in which birds - segregated by species - slept every night.

find them all in un lun dun.