The phrase "was the back of" can be replaced with a variety of synonyms to add more detail and depth to your writing. Some alternatives to consider include "behind," "rear," "posterior," "hindmost," "tail end," or "trailing edge." Each of these words can be used in different contexts to convey a slightly different meaning, so choose the synonym that best fits the intended tone and context of your writing. Using synonyms is an excellent way to keep your writing fresh and engaging while avoiding repetition and redundancy.