Metaphor occurs as one idea or element is defined by mentioning another element of idea that has some similarity. This differs from simile because the comparison does not include explicit words such as "like" or "as". In the case of "The line to get into the concert was a river, snaking through an endless valley" the author uses metaphor because to describe the line to get into the concert as long and moving the author defines it by mentioning a river "The line..was a river", also as the line was long the author defines it as "snaking through an endless valley".
I would say Heaven is a place where I can live out my wildest dreams. It is a place where I can have as many dogs as I want with no worries about affording their care or having them get sick. It is a place where money does not matter whatsoever and everyone can live happily and peacefully.
