Art Nouveau is an architectural style that was popular in the late 19th and early 20th centuries. It is characterized by its use of organic forms and flowing lines.

Josef Hoffmann was an Austrian architect who was a member of the Vienna Secession. He designed the Esperanto House in Vienna, which was built in 1912.

The Esperanto Museum and Collection is located in Budapest, Hungary. It is the largest Esperanto museum in the world.

Berlin has the most Esperanto-speaking inhabitants of any city in the world.

The Esperanto Monument is located in Rotterdam, Netherlands. It was erected in 1955.

The Second World Esperanto Congress was held in The Hague in 1920.

The Esperanto flag is a green flag with a white star in the center.

La Espero is the Esperanto anthem. It was written by Kalman Kalocsay.

L. L. Zamenhof was a Polish ophthalmologist who created the Esperanto language.

La Esperantisto is the oldest Esperanto magazine. It was founded in 1889.

Akademio de Esperanto is the Esperanto language academy. It was founded in 1905.

Plena Ilustrita Vortaro de Esperanto is the most comprehensive Esperanto dictionary. It was compiled by Gaston Waringhien.

Plena Gramatiko de Esperanto is the most comprehensive Esperanto grammar book. It was written by Bertilo Wennergren.

Unua Libro is the first Esperanto textbook. It was written by Lidia Ligero Zamenhof.

La Juna Esperantisto is the Esperanto children's magazine. It was founded in 1905.