Linkin Park went off-the-wall on sacred ground recently -- stopping by one of the holiest places on Earth to pay their respects ... the Wailing Wall in Jerusalem.


As for the yarmulkes, most of the guys aren't part of the Tribe ... but it's considered customary to wear the headgear at the Wall.

FYI -- the band performed last night in Tel Aviv. Tickets were reasonably priced.

Linkin Park endures the same pain millions cope with daily -- a bad back. But the band will not take the pain lying down -- especially when millions of bucks are on the line.

Backstory: Linkin Park's lead singer, Chester Bennington, injures his back ... back in 2008 ...while putting a toy together for his son. The band was forced to back out of 6 concerts.

Backstab: The band filed a claim with Lloyds, London insurance company for lost profits from the concerts. The insurance company refused to pay, claiming Bennington's injury was preexisting at the time the insurance policy was issued. Bennington begs to differ.

Comeback: Linkin Park has filed a lawsuit against Lloyds, asking for millions of bucks.