Like leaping from Kiyomizu Temple

Kiyomizu Temple is all lit up at this time of year so that people can enjoy night views of the 紅葉 (momiji - autumn leaves). I went along last night and learnt this expression:

清水の舞台から飛び降りる - きよみずのぶたいからとびおりる = literally to leap from the platform of Kiyomizu Temple. It's pretty high up, so to resolve to leap from such a great height would require a lot of courage. Hence the meaning of this expression is to leap into the dark; to take the plunge; to jump in at the deep end.