illegally-dug tunnel that was being used by young Orthodox Jewish men in an attempt to link the building to a nearby ritual bath.

It remains unclear why the young men are so attached to the property they were accessing illegally - they have for years been at loggerheads with the synagogue over who owns the main property, but the appeal of the ritual bath or mikvah is unclear.

https://www.dailymail.co.uk/news/article-12942605/Inside-secret-tunnel-built-extremist-Jewish-students-linking-historic-cleansing-bath-Brooklyn-synagogue-discovered-homeowner-heard-suspicious-noises-night.html

A member of Brooklyn's Satmar Hasidim fundamentalist branch of Orthodox Judaism, Nuchem designs and repairs mikvahs in compliance with Torah Law. The mikvah is a ritual Jewish bathhouse used for purification. Devout Jews are required to cleanse themselves in the mikvah on a variety of occasions Many of the devout also purify themselves before and after the act of sex and before the Sabbath.

On a visit to Jerusalem in 2005, Rabbi Rosenberg entered into a mikvah in one of the holiest neighborhoods in the city, Mea She'arim. "I opened a door that entered into a schvitz," he told me. "Vapors everywhere, I can barely see. My eyes adjust, and I see an old man, my age, long white beard, a holy-looking man, sitting in the vapors. On his lap, facing away from him, is a boy, maybe seven years old. And the old man is having anal sex with this boy."

https://www.vice.com/en/article/qbe8bp/the-child-rape-assembly-line-0000141-v20n11

Pic related Rabbi Rosenberg inspects a ritual purification bath, known as a mikvah. In 2005, he witnessed a young boy being raped inside a similar bath.