Anyone strolling down Marlborough Street in tony Back Bay might miss the French Cultural Center of Boston if they weren’t looking for it. The nonprofit’s home looks like any other historic mansion lining the street, but inside is a Francophile’s dream. Dedicated to ensuring the growth of French language and culture in present-day New England, the organization boasts the second largest private collection of French books in the United States – more than 25,000 publications – as well as periodicals, DVDs, CDs and more. The cultural center is also home to a school that offers language classes for both adults and children. Combine all of that with an array of lively cultural events held throughout the year, from art exhibitions and lectures to cooking demonstrations, and the French Cultural Center becomes one of Boston’s hubs of French culture.