Case study: How OHRIZON facilitated the visit of the Crypt of Boulogne-sur-Mer with a multimedia audioguide

The Crypt of the Basilica of Notre-Dame in Boulogne-sur-Mer, one of the largest crypts in France, has transformed its visitor experience with an innovative multimedia audio guide. The application developed by OHRIZON, available on smartphones and tablets, offers visitors intuitive access to over 60 points of interest, while guiding them through the crypt's labyrinth of rooms and corridors. The system is based on a single database, enabling simple and efficient updates for site managers. The application, with its sleek design and user-friendly interface, has modernized the way visitors explore this historic and archaeological space.

The Crypt of the Basilica of Notre-Dame-de-l'Immaculée-Conception in Boulogne-sur-Mer is a major historical site, open to the public since May 2015 after an ambitious renovation program. Accidentally discovered during the construction of a church in the late 19th century, the crypt is an exceptional testimony to over 2,000 years of history, housing rich archaeological collections. As France's largest crypt, it attracts many visitors curious to discover the history and heritage on display.

One of the main challenges for the town of Boulogne-sur-Mer was to make this crypt, with its labyrinthine design and complex space, accessible to visitors while modernizing the experience. The site also had to meet the needs of a diverse audience, from history buffs to families, by including content adapted for younger visitors. In addition, another major challenge was to provide a multimedia audioguide adapted to a difficult physical environment for the technology, notably due to humidity and space constraints in the crypt.

Finally, the management of information on this complex site needed to be simplified for the Heritage department, with a solution enabling content to be updated centrally and efficiently.

To meet these challenges, OHRIZON has designed a multimedia audioguide application, available on tablets and smartphones. The application's interface has been carefully designed to be ergonomic and intuitive. Visitors can easily access content by simply typing in the number corresponding to the element of the crypt they wish to explore. This approach makes discovering the 60 points of interest fluid and interactive.

The application also includes an interactive map that guides visitors through the crypt's vast network of rooms and corridors. This map, integrated with the site's database, ensures that visitors find their way around this religious heritage, while offering rich contextual information on each point of interest.

Another essential aspect of the solution was to make the application reliable despite the physical conditions of the crypt. OHRIZON integrated robust technology to enable synchronization with the site's database, guaranteeing a consistent, uninterrupted visitor experience. The centralization of information in a single database means that site managers only need to update the information once a year.

Since the implementation of the audioguide, the Crypte de Boulogne-sur-Mer has seen an increase in visitor satisfaction, thanks to improved accessibility and an enriched visitor experience. The application has particularly appealed to families and young visitors, with an easy-to-use interface and fun content for children. Visitor feedback also highlights the quality of the information provided, which helps visitors to better understand the history and archaeology of the crypt.

For the Heritage department, the application has brought great efficiency by simplifying content management, reducing maintenance costs and facilitating the integration of new information or temporary exhibitions. Synchronization between the website and the application has centralized data management and facilitated updating.

Thanks to OHRIZON's expertise, the Crypte de Boulogne-sur-Mer was able to modernize its approach to cultural mediation, while respecting the unique challenges presented by this historic site. The multimedia visioguide application has made this crypt, often perceived as complex, accessible to all audiences. OHRIZON has combined technology and simplicity to create an immersive, educational and enjoyable experience, transforming the way visitors explore this fascinating monument.

Since 2026, the application, available on the Google Play and Apple Store stores for direct download from your smartphone and available on site using tablets, has proved its relevance.

If you want to enrich your visitors' experience by offering a modern, interactive experience, OHRIZON can help you develop a customized solution tailored to your needs and your assets.