1) The first modern Olympic marathon race was held at the 1896 Olympics in Athens and has since become one of the most iconic and challenging events in athletics.

2) The first graphical web browser, Mosaic, was released in 1993 and played a key role in popularizing the World Wide Web.

3) The universe is estimated to be around 13.8 billion years old.

4) The first modern health insurance policy was introduced in Germany in the late 19th century.