Answers revealed in the comments.
There are two buildings in Pennsylvania designated as UNESCO World Heritage Sites. One was originally built in the 18th century, and the other was built in the 20th century. Name either of those buildings.
According to Wikipedia’s home screen, there are more than 6.1 million articles on the website that can be read in English, the most of any language. Of the languages displayed on the home screen, name one of the other two that exceed two million articles.