あんなきれいな日没は見たことが無い。

such (about something or someone distant from both speaker and listener, or about a situation unfamiliar to both speaker and listener); so; that; sort of

pretty; lovely; beautiful; fair; clean; clear; pure; tidy; neat; completely; entirely

sunset

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

to see; to look; to watch; to view; to observe; to look over; to look on; to assess; to examine; to judge; to look after; to keep an eye on; to take care of; to view (e.g. flowers, movie); to try; to try out; to see that...; to find that...

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

nonexistent; not being (there); unpossessed; unowned; not had; unique; indicates negation, inexperience, unnecessariness or impossibility; not ...; to not be...; to have not ...