I’ve recently added several good to great destinations.

Three are chained libraries with medieval books:
* Hereford Cathedral Library, UK
* Malatestiana Library, Cesena, Italy
* Librije, Zutphen, the Netherlands

Four are in France:
* A language museum in Paris
* The Museum of History and Culture of the Deaf, Louhans
* The bilingual (French-Corsican) ‘House of memory’ museum, Corsica
* The Esperanto Museum in Gray

Three are in the Republic of Ireland:
* George Bernard Shaw Birthplace in Dublin
* National Print Museum in Dublin
* The Atlantic cable station at Valentia Heritage Centre in Knightstown

The others are all over Europe, from Central Norway to Macedonia: 
* The Old Languages department of the famous Capitoline Museums in Rome
* Museum for the Deaf, Trondheim, Norway
* Trilingual village of Bivio (Beiva, Stallen), Switzerland
* Permanent exhibition on lexicographer Van Dale, Sluis, the Netherlands
* Den Doolaard House Museum, Ohrid, Macedonia

Hundreds more are listed in the guide. Download it!