On one side of the Atlantic Ocean is Philadelphia, one of the most historic cities in the United States and the place where the Declaration of Independence was signed, and as such, the City of Brotherly Love has a large number of historical treasures.

Some are very well known — like the Liberty Bell — while others are more obscure and older than that. For example the letters written by Spanish writer Miguel de Cervantes. The Rosenbach Library has three of the 12 letters of this kind that exist in the world.

On the other side of the ocean and 3,579 miles (around 5,759 kilometers) away is Simancas, Spain. It is a small village with no more than 5,000 inhabitants, renowned in Spain for being the place where the first Official Archives of the Spanish Crown were established in the 16th century.

Despite the distance, serendipity connects these two places; that is serendipity and Don Quixote’s author connect the two sites — because Simancas and Philadelphia share two pieces of the same letter, and nobody was aware of it.

This discovery was made a few months ago, when the Spanish publisher Círculo Científico-Taberna Libraria decide to celebrate the fourth centenary of the death of Cervantes with a special edition of the 12 letters written by the author.

It was one of the experts who is working on the project, a professor of Paleography, Elisa Ruiz, who realized that a portion of one of the letters of the Rosenbach Museum was missing. Ruiz discovered that missing portion in Simancas.

It is unknown if the two pieces of the letter will be reunited and became one, as they were when Cervantes held them in his hands more than 500 years ago.