From 2018 to 2022, SISSO supported the Château de Fontainebleau in its communications around the restoration of the Escalier en Fer-à-Cheval. The Château called on SISSO to develop, create and manage a communications campaign as part of its fundraising campaign to finance the restoration work. SISSO set up a complete campaign, based on a donor-centric strategy. SISSO then worked with the establishment to document the progress of the work through videos. In 2022, the agency also developed the communications campaign for the inauguration of the restored staircase.

Furthermore, the agency regularly creates communication tools for exhibitions at the Château de Fontainebleau, such as the installation of interactive works on tactile tables, or the production of teasers. In 2020, the agency was selected for the audiovisual production framework agreement set up by the institution.

Since summer 2022, SISSO has also been in charge of managing the institution's social networks (strategy, editorial planning, content preparation and community management).