The phrase "very large size" can be replaced with a plethora of synonyms to add variety and impact to your writing. Here are some suggestions: enormous, massive, colossal, mammoth, gigantic, humongous, jumbo, mega, hulking, towering, substantial, considerable, vast, bulky, and oversized. These words can enhance your descriptions and help you to communicate the impressive size of an object or space. Remember to choose your words wisely and consider the context of your writing to ensure that the synonym matches the tone and intention of the sentence.