One hundred years ago, on 20th February 1915, the Panama Pacific International Exposition (P.P.I.E), opened in San Francisco, California. The Exposition was officially aimed at celebrating the completion of the Panama Canal, which was inaugurated on 15th August 1914. After the earthquake and the fire of 1906, this Expo became a huge economic opportunity for the city. It was a big success and it did a lot to boost the bay's morale and to reassert the value of San Francisco.

Despite the First World War, 29 foreign countries and 32 American states and territories participated in the Expo. It was a place to exchange views, art, products; a place to write the future in a troubled present.

The Expo was built in three years. The most well-recognized buildings were the Tower of Jewels and the Domed City in which each palace had a central dome at the top surrounded by smaller domes. The majority of buildings and palaces were built with materials similar to plaster and they were designed to last only for the Expo period. A notable exception is the Palace of Fine Arts; it was not demolished and it was entirely rebuilt in the '60s. Today, it is a centenarian witness of this great Expo.

The Panama Pacific International Exposition 1915 was the first Expo to widely use the "indirect lighting". These lights reflected the appearance and the colour of the buildings. During misty evenings, the fog got different tints and on clear nights, a stationed locomotive made steam clouds in order to get a similar result.

The main attraction was the topographical model of the Panama Canal, which covered five acres. A movable platform (1440 feet long for 1200 people in 144 carriages continuously connected) went round the model in 23 minutes for the sum of 50 cents. The mechanism presaged the famous "Futurama" of the New York Exhibition in 1939.

100 years ago, about 19 000 000 visitors were present during the entire Exposition period, that is to say 289 days.100 years later, the Panama Canal is still a strategic crossing point for navigators and today San Francisco is the third most popular tourist destination in the United States.