The phrase "exists on" can be replaced with a variety of synonyms to add diversity to your writing. Some synonyms with similar meanings include "can be found on," "is present on," "occurs on," "resides on," "subsists on," and "rests on." Depending on the context, other synonyms could include "exists within," "is located on," "dwells on," "rests upon," or "is situated on." Using different words to express the same idea can spice up your writing and keep it from becoming repetitive. Experiment with these synonyms the next time you need to describe where something exists.