To find out what stairs you can currently challenge someone in, first go to the Main Stairs Page, then click on "Show your stairs only" link. The ones in BOLD are ones you can make a challenge in. .
Maybe its just me... or the "retirement" isnt really for vacation, but it took me half an hour to retire in all my stairs. (click stairs, click to my stairs, click to a specific one, scroll down,click to retire,scroll down,click to be sure,go to main stairs, go to my stairs only, find new game, and repeat)
Does it make sense to be able to start retirement in all our stairs at once? Or at least streamline the process so after we retire one, it takes us back to our own stairs page?