Looking north from the tower of Notre Dame - St. Jaques Tower and Montmarte Heights in distance, Paris, France

Stereographs are devices capable of building a three-dimensional​ image out of two photographs that have about two and a half inches difference between them so that it could imitate the two eyes’ real field of view. Combining these images into a single one with the help of stereoscope, a person can experience the illusion of the image’s depth. Stereoscope uses the same principle as in human binocular vision. Our eyes are separated by about two inches, so we see everything from two different angles. When the brain combined those views in a single picture, we get the spatial depth and dimension. Stereographs were extremely popular between 1850 and 1930 all around the world. Millions of stereographs were made during that time. There was a broad range of themes: landscape, travel, historical moments, nature disasters, architecture and many others. Nowadays, simply launch this collection full screen and put your mobile device in Google Cardboard Viewer.

After the Paris exposition of 1889, France gloried in her triumph. The time between the expositions of 1889 and 1900 was an era of economic prosperity. When Germans announced they want to hold the next world expo, French politicians, industrialists, and intellectuals realized that the country which hosted the exposition at the threshold of the new century "will define the philosophy and express the synthesis of the 19th century." Participating nations architects were given complete freedom to construct their national pavilions in any style, and display whatever they wished therein. The sole limit was the space assigned to each. The buildings of the 1900 exposition fall into two distinct categories, each representing an essential element of the spirit of 1900: Traditionalist 19th century-styled and Art Nouveau - the new style appropriate to the twentieth century. The pavilion to symbolize the new era was the Palace of Electricity. Many expositions gave visitors an illusory trip to remote lands. The Trans-Siberian was a simulated Peking to Moscow railway and "Tour of the World," located at the base of the Eiffel Tower featured moving canvas of the sights and people throughout the world. More than 83,000 exhibitors and attendance of 51 million visitors made it the largest of any exposition. The 127 congresses had attracted over 80,000 participants. The Gare d'Orsay railroad station (now the Musée d'Orsay), and two of original entrances of Paris Métro stations by Hector Guimard., and the Pont d’Alexandre, the Grand Palais and the Petit Palais opened with the exposition. The exposition Universelle of 1900 was the last of its kind held in France.

Île de la Cité is an island in the River Seine, once known as Lutetia, and is the oldest settlement in Paris, France. It is one of two natural islands in the river, the other being Île Saint-Louis. The island has a rich history that dates back to ancient times. It is believed to have been settled by the Parisii, a Celtic tribe, in the 3rd century BC. In 52 BC, the Romans conquered the island and established a city there, which they called Lutetia. The island was the site of several important events in French history, including the signing of the Edict of Nantes in 1598 and the French Revolution. Today, Île de la Cité is home to many famous landmarks, including the Notre Dame Cathedral and the Palais de Justice. Île de la Cité with sights such as the Pont Neuf, the Pont de l’Archevêché and Notre Dame cathedral, makes it the central crossroads of the city, which grew outwards from here. Ile de la Cité is the perfect place for a riverside picnic.