Yeah, the Arena was/is a smaller venue on the Seattle Center location - I think it seats 5000 for hockey, etc. The big shows - Beatles, Stones, Who, Yes, Zeppelin, CSNY - were at the Seattle Center Coliseum.
Jimi Hendrix played at the Center Arena in 1968 and the Coliseum in 1969.
Wish I'd been older and had caught one of those shows.
Now the "Hendrix museum" aka Experience Music Project is right there at Seattle Center.