Originally built as the Exposition Building in 1912, this arena was also renovated and repurposed for show space at the fair.
Then:
2011:
After the fair, the arena housed an ice rink and for a time was home to Seattle's hockey team, the Thunderbirds. It became known as Mercer Arts Arena, and maintained the same look for years and housed concerts and other events.
UPDATE (2017): Sadly Mercer Arena was demolished in 2017, to make room for a new office for Seattle Opera.