I know a good way to wreck your knees.
Stairs are my get fit secret.
I get a bit claustrophobic in lifts...
Also, one particular stairwell always smells like chai tea!
Better than the stairs in my building. Because the construction and lack of signs which they still haven't fixed - you don't know which door is alarmed until you open it. Then you get people teasing you because THEY take the lifts even to get to the 1st floor.
Our office also gets at least 5 ambulance visits a year - so yeah.