It is a Jewish tradition of the Orthodox mainly on 33 of the Omer counting ( called Lag B'omer) to go to the grave of Rabbi Simeon bar Yochai. In the Talmud it states that on this day the plague which had wreaked havoc amoung the students of Rabbi Akiva ( thought to be the Messiah at one time) , ended, and it is a happy day of rememberance.
Rabbi Simeon bar Yochai is the author of a book on mysticism and Jewish mystic on this day visit his grave in Northern Israel, Meron. Mainly these are the Satmars, the very ultraorthodox. Many travel from Brooklyn NY USA, even for this day. It is also a tradition that a boys first haircut be performed at the gravesite and many a father takes his young son ( around 3yrs old) to do this. They believe this brings them 'luck'.
I am sure if you google lag B'omer and Rabbi Simeon bar Yochai you will find all sorts of info, also google the word miracles with it and see what you find.