You should always provide more context. The short answer, is "you could, but almost certainly don't mean to." I believe you mean to say "It is called the land of watches." You could also use the contraction "It's" instead of "It is." The word "is" (from "to be") is necessary to form the passive voice. The meaning is similar to "People call it the land of watches."
In theory, you could use the active voice where "it" is performing the action, ie. making the call.. however, "it" normally refers to an inanimate object, incapable of initiating a call, and "land" is also an inanimate object, incapable of receiving calls. The sentence without "is" may be grammatically possible, but doesn't make sense in the real world.