You can also say: "Isn't there another way?" For example: If you are lost, you can say: "Isn't there another way?" or "There has to be another way!"

It depends on the context. Most likely interpretations are: Aren't there always other choices besides this one? Aren't there always other ways of doing this than this way? ['this' being whatever needs to be done] An alternative in this case refers to some choice other than the current one. It is always implied: "Aren't there any alternatives [ to some choice ]."

"Aren't there always alternatives?" means that there is always another way or method of accomplishing a task