Knockroe Passage Tomb near Windgap in County Kilkenny was only rediscovered during the 1980s. Like Newgrange, the dawn light on the Winter solstice aligns with the structure, but unlike Newgrange so does the sunset on the same day.
Both sunrise and sunset (and indeed all day) gatherings at Knockroe seem to have become common if this article from TheJournal.Ie is anything to go by.
Unless things have changed the site isn’t signposted from the main road, if anyone reading this is seized with an urge to visit.
Here is the 2015 sunset on Youtube:
Here’s a video of Knockroe set to the music of Philip Glass: