Based on the provided source material, there is no information confirming that Letta is a city in Liechtenstein. The name "Letta" primarily refers to an Italian surname and an African given name.
Notable individuals associated with the name include Gianni Letta, an Italian politician and member of Forza Italia; Enrico Letta, a former Prime Minister of Italy; Lencho Letta, an Ethiopian politician and activist; and Letta Mbulu, a South African jazz singer.