(Translated with Google Translate)
On January 14, 1890, a treaty was signed between the municipality of Mers-les-Bains and Mr. Deflers for the acquisition of a building used as a casino, for an amount of 40,000 francs. This was rebuilt on the site of the first hot baths establishment, slightly set back (AD Somme, 99 O 2594). It is a pavilion from the Universal Exhibition of 1889, formerly the Duval restaurant, to which two bodies have been added on the ground floor at each end. This fourth casino is a building with an elongated plan, with corner pavilions, the central part of which consists of a square floor. Made of wood, it has lambrequins and large windows. In good weather, fabric awnings protect the terrace. Its dimensions are 39.39 meters long and 17.30 meters wide and 7.84 meters high under the ceiling in the central part. The cover is in zinc slate. This new casino projects 10 meters from the extended line of the facade of the Oppenheim house (block 15) and rests on a masonry base (AD Somme, 99 O 2594). In 1890, the central body included the performance hall as well as a location for the orchestra, a room for small horses and a coffee room in the left pavilion, a conversation room and a reading room in the pavilion of law.
In 1897, the casino scene was enlarged by the architect Edouard Boeuf, for a price of 1,000 francs. In 1907, a covered and glazed terrace was added on the side facades and on the front facade, on the plans of the architects Dupont and Lasnel, installed respectively in Mers-les-Bains and Eu. This gallery receives a café and a track of ‘ music hall’ with orchestra. At that time, the Grand Salon was transformed into a theater. In 1911, a rental lease was signed with Magherini (owner residing in Paris) until 1922, when we learn that the building consists of: a large main building in the beach esplanade composed of a basement -ground and a ground floor with glazed terrace; the basement is intended to serve as a cellar and equipment shed. Magherini may assign part of it to his personal accommodation. The ground floor is divided into eight rooms including in the center the performance hall and the music hall. According to the Joanne guide of 1912, the curtain of the theater is painted by Chapron. The garden adjoining the casino extends to the main road. There are six tennis courts . . . Requisitioned by the German army during the Second World War, the casino was destroyed in September 1943 to facilitate the installation of artillery pieces
Région Hauts-de-France – Inventaire général.