YTbErYb, Sc?

https://en.wikipedia.org/wiki/Ytterby ("Ytterby is the single richest source of elemental discoveries in the world; the chemical elements yttrium (Y), terbium (Tb), erbium (Er), and ytterbium (Yb) are all named after Ytterby")

YTbErYb, Sc

Eu

You could *almost* squeeze in a seventh, as Holmium is named after the city of Stockholm; and the city Ytterby is in the greater Stockholm area, in Sweden. Sadly, Ytterby doesn't seem to be contained in any political division with a proper name containing "Stockholm". So, that doesn't work. (Though Ytterby is in a geographic region called the "Stockholm archipelago").

He/she forgot Na for National.

Except all of the elements in the address above were at least partially discovered at that address or by teams with connections to that lab. Although usually it is a joint discovery with at least one other lab.

Na is a bit older than those labs.

Berkeley Lawrence elements: https://www2.lbl.gov/Science-Articles/Archive/new-elements-h...

Lawrence Livermore elements: https://www.llnl.gov/article/41866/lawrence-livermore-credit...