The phrase "was impressive" can be swapped out for a variety of synonyms to add nuance and depth to your writing. You could use "striking" to emphasize the visual impact of something, or "remarkable" to convey a sense of amazement. "Notable" suggests something that stands out from the crowd, while "imposing" implies a certain grandeur or power. "Incredible" conveys a sense of disbelief, while "exceptional" suggests something that surpasses standards or expectations. No matter which synonym you choose, using a diverse range of language can help to make your writing more interesting and engaging for your audience.