Panama-Pacific International Exposition, 1915, an exposition held at San Francisco to celebrate the opening of the Panama Canal. The exposition grounds were on filled land along San Francisco Bay. This was the first exposition to offer airplane rides. The chief architectural feature was the Tower of Jewels, decorated with 125,000 glass prisms. Total attendance was 18,756,148. The Palace of Fine Arts, the exposition's only permanent building, was restored in 1968.