Ytterby, village in Sweden where the rare-earth minerals were first found

What was so special about Ytterby? No less than four rare earth elements were found there and named for the village: not just Erbium, but also Terbium, Ytterbium, and Yttrium.

What are the chances that four new substances will be first found in the same small village where a scientist just happens to be working? Are the "rare earths" really more common than the name implies, and might have been found near just about any laboratory if the right person had been looking?