This photo below was probably taken around 1974 at the Muscle Beach Weight Pit in Venice, California. For whatever reason, Musclemag International photoshopped jeans on this photo(see below) and placed it on the cover of one of their “Arnold Specials”. The original Muscle Beach where Steve Reeves and George Eiferman et all used to hang out was at a different location closer to the Pier. According to Wikipedia, the original Muscle Beach’s tumbling platform, created in 1934 and located in Santa Monica, was shut down in 1959 due to day to day maintenance and supervision issues.
After the waning of the original Muscle Beach, bodybuilding attention went to the Venice Beach Weight Pen, created in 1952, operated by the Los Angeles Recreation and Parks Department and at a different location in Venice. That very Weight Pit is where Arnold Schwarzenegger is in the above photo. The Weight Pit, as it looked in the 1970s, no longer exists but was completely revamped in 1990 and retains that new look to this day. The new Weight Pit was basically built on top of the old one. They are at the same location.
Below is historic footage of the original Muscle Beach in Venice California, 1955. Acrobatics were popular at the time but seem to have been upstaged by weight training. Cotton Candy was 10 cents at the time(as the sign says) and Elvis Presley hadn’t yet hit the big time.
Below is some cool 1970s footage of what appears to be at the location of original Muscle Beach in Santa Monica, near the pier. Apparently the Original Muscle Beach still had life in the 1970s although the bodybuilders shifted to Venice and created the new Muscle Beach.