Au, is the name of several towns in Austria, Germany, and Switzerland.
Ea, a town in the Basque Country, Spain (the shortest place name in Spain)
Ib, is a railway town in India
Ob river, town, and gulf in Russia
Also, Ur is an ancient city in Mesopotamia and a town in Catalonia.
There are other vilages, rivers and valleys worldwide with two letter names.
NOTE: Fairly lengthy list follows at:
https://en.wikipedia.org/wiki/List_of_short_place_names
[Note added -- Zbeck]