The prestigious Sandelin mansion was built in the 18th century in the classical French style, around an inner courtyard and surrounded by a garden. It has, for the last hundred years, held sumptuous collections of art works and artefacts ranging from the 11th to the 19th century. Over 3,000 items, displayed in 21 rooms on 3 floors, testify to the rich past of the town, showing the tastes of contemporary collectors and reflecting the extraordinary diversity of the ceramics produced during the modern period in Europe and Asia. The museum is furnished with the vestiges of Saint-Omer's emblematic buildings, laid out in atmospheres that are sometimes crypt or church-like, with reconstitutions of curiosity cabinets and reception rooms that recall the original purpose of the Sandelin mansion. A new piece from the museum's collections is put in pride of place every month, at the starting point of the tour. A place in which to take your time looking around and dreaming of the past.