The Museum of Quidditch is located in London, although we don’t know its exact location.
A medieval broomstick predating the development of the Cushioning Charm (QA1).
The diary of Gertie Keddle, who lived on the edge of Queerditch Marsh in the eleventh century (QA3).
A twelfth-century tapestry depicting a group setting out to catch a Snidget (QA4).
A letter from Modesty Rabnott to her sister Prudence, describing the incident that led to the inclusion of the Snidget in the game (QA4).
There might be Museums of Quidditch in other countries as well for, although the sport originated in Britain, it is of course now popular worldwide. The museum in London, however, is the only one for which we have direct evidence.
From the Web
Harry Potter Wiki: Museum of Quidditch