At some point, we all travel and explore new places. While you're globe-trotting, don't forget to visit libraries! Seriously, some libraries are tourist attractions and well-worth a visit. Even the New York Times has recognized this insider's tip!
You could start close to home, in Washington DC, at the Library of Congress. The Jefferson Building, near the Capitol, is considered by many to be the most beautiful building in the city. See the Gutenberg Bible! See Thomas Jefferson's library! they always have a featured collection on display. And it has a great gift shop!
Further afield, the Morgan Library and Museum in New York has a fabulous exhibit space, beautiful architecture, J.P. Morgan's private library, and a great gift shop. This library/museum also always features exhibits from its treasures.
Going west? The Huntington Library in San Marino, CA has art collections and botanical gardens in addition to the library. It's known for a splendid collection of the history of science, among other things. It also hosts exhibits, and has a great gift shop.
Going abroad? The Bibliothèque Nationale in Paris is a fabulous space to visit, with exhibits, great collections, a spectacular view, and - a gift shop! The British Library in London is fabulous. And the national library in Florence, Italy - Biblioteca Nazionale Centrale di Firenze - awaits you too. In Madrid, the Biblioteca Nacional is a destination. You could even visit the National Library of China in Beijing, Russia in St. Petersburg!
Sure, all these libraries have great websites, and their catalogs are online. But it's not just about the books (although they have fantastic collections). Experience the space, the architecture, the exhibits, and, well, the great gift shops!