Rare 8mm footage of Led Zeppelin performing at Kezar Stadium in San Francisco, 1973.

That's a big outdoor stadium.

Jimmy Page:
"What I remember about that 1973 tour is that we arrived in America and we did 53,000 at Atlanta and then 55,000 at the following concert in Tampa, Florida — it was quite clear that if people were going to come along to see us in those kind of numbers we weren’t going to have problems doing concerts that would fulfil the demand. It was phenomenal though — the audience reaction was just so with us, y’know."

Huge outdoor shows.