Anywhere can work!
I think the key to making a place or nook for the baby to play is SAFETY! Find any area of your home that you can perhaps monitor from an area you are at a lot.. make sure outlets are covered, cords put away, and there isn't any furniture that can be hit or tipped. I would put a soft mat perhaps.. so they get used to WHERE they can play, as well as baby gates where appropriate! Soft tubs or bins for toys are nice, so the baby can get used to using them themselves.. but the spot doesn't have to be huge.. just a cozy place so they can play! Lately I have seen darling play TENTS! So cute.. but just keep a watchful eye always!