If I don't pay a debt, then the creditor takes my goods. Why, then, do Greek creditors not take Greece?

Normally, when you don't pay a debt, your creditors take your goods (house, car, etc). If Greece cannot pay its debt, can its creditors take Greek goods (structures, cities, industries, lands, etc)? Can Germany, or other organizations, become owners of Greece? Maybe that's a silly question, but for a non-expert it sounds logical.