The Mathematical Institute of the University of Seville holds a blog in which one can read about mathematical-related topics. Here you will find the entries that I wrote touching upon historical episodes: 

• ¿De qué (no) está hecha una línea? (here).

• The most beautiful inequation in mathematics (here).

• π: “Una bella expresión que revela la naturaleza enteramente trascendente de este famoso número” (here).