I’d hardly call bike locks ‘prison’, but they are a bit unsightly, for good reason, though. ‘Ivy’, by Sono Mocci from Italy is on the ‘seoul cycle design’ competition short list. It really needs no explanation, but just in case you were wondering, yes, it’s a bike lock disguised as ivy, the green stuff that grow rampant on the sides of houses. If I were you I’d stick to a U-lock, and use this to keep my tire or seat in check.
The Ivy lock is made from silicon and steel, and uses a 4 dial number lock.