Original: One seat from Met Stadium was placed in the Mall of America at the exact location (including elevation) it occupied in the stadium, to commemorate a 520 f home run hit by hall-of-famer Harmon Killebrew on June 3, 1967.
Simplified: One seat from Met Stadium was placed in Mall of America at its exact location (including elevation) in the stadium, to recognize a 520 foot home run hit by hall-of-famer Harmon Killebrew on June 3, 1967.