The German was asked on Sky Sports' Monday Night Football what is more impressive out of Anfield's Kop end or Dortmund's Yellow Wall.
Klopp, who has also previously managed at Mainz, was diplomatic in his answer as you would expect.
"It's different," he said.
"But I can say, nothing compares to the Yellow Wall because there's 27,000 people standing there.
"That is quite impressive.
"Now we have a new stand at Liverpool which is 22,000 sitting. I've never seen something like this, but it's quite impressive.
"But the Kop created the best half-hour I've had in football until now.
"It was the last half-hour against Dortmund (in the Europa League last season).
"I've had a lot of nice atmospheres, brilliant atmospheres, but this half an hour was the best I've had.
"Hopefully not the best we will ever have but until now, it was outstanding.
"I don't want to compare. I'm a really lucky guy that I've been at two wonderful clubs before and can now work here.
"The Kop is an impressive place and I love to play in front of them but as I said, Mainx and Dortmund are two nice places too."