Serendipity

The act of finding something valuable or interesting when you are not looking for it. Coined by English author Horace Walpole in the mid-1700s, crediting it to a fairy tale he read called The Three Princes of Serendip. In the tale, three Persian princes sail to an island called Serendip (today known as Sri Lanka) to find their fortunes, making wondrous discoveries along the way.

E.g. It had to be serendipity that I found my dream house during a random drive in the country.