The Universitat Politècnica de Catalunya (UPC) is pleased to announce the 25th International Conference on Transparent Optical Networks (ICTON 2025), which will be hosted in Barcelona, Spain, from July 6th to 10th, 2025. This will mark the third time that ICTON takes place in Catalonia, following its previous editions in Barcelona in 2005 and Girona in 2017. Barcelona, the vibrant capital of Catalonia, is a city renowned for its rich history, stunning architecture, and vibrant culture. Situated on the northeastern coast of Spain, Barcelona offers a perfect blend of modernity and tradition. Its iconic landmarks such as the Sagrada Família, Park Güell, and the Gothic Quarter are just a few examples of the city’s architectural wonders.