Dirt Simple

Seems the ancient Druids new about the healing powers of this location, and now we know as well:

Researchers analysing soil from Ireland long thought to have medicinal properties have discovered that it contains a previously unknown strain of bacteria which is effective against four of the top six superbugs that are resistant to antibiotics, including MRSA.

Read more at: https://phys.org/news/2018-12-bacteria-ancient-irish-soil-halts.html#jCp