Both signs are found at Shinto shrines. The first sign explains how to purify yourself (in preparation for praying and performing any other tasks you have to do there). You rinse one hand, then the other, then the mouth:
Another shrine is well known for its "healing stone". Here it is:
This diagram explains how to obtain the benefit of the stone. No problem if you can't read Japanese, all the basics are there! Just pray for a few moments; rub the stone with your hands; then touch your hands to the afflicted part of your body.