Visited this site in September 2019. We arrived on Monday and there were not many people. Visitor center is still under refurbishment (the guide told that probably only 2-3 weeks are left to complete the works). We received free tickets to Knowth and Newgrange and visited both.
Knowth comprises one large mound and 18 surrounding small mounds. Two passage tombs are not accessible to tourists (only a glimpse into one of the passages), but there is a showroom, where the video demonstrates the impressive interior of the passage. Large mound’s perimeter is circled with 127 big stones, many of which are nicely carved. The guides specifically emphasize that the site has been continuously used from the ancient times until the late medieval period (and of course, the remind that these tombs are older than the pyramids). Knowth also has a reconstruction of timber monument probably used for rituals. It is possible to climb the large mound and enjoy a beautiful view to the surrounding green valleys.
Newgrange is a single large passage tomb with 97 kerbstones with richly decorated main entrance stone; however, other stones are not so well carved as at Knowth. The highlight is 5,000-year-old passage, 19 meters long with a bit narrow stretch at the beginning, leading to a chamber with round roofs and three tomb chambers. The guide highlighted that after 5,000 years of Irish rains the roof has been still water proof! Inside stones have both historical visitors’ graffiti and ancient spiral carvings. The guide also turned off the light and demonstrated how the sun is entering the chamber during the winter solstice.
Dowth is not yet ready for tourist visits, but it could be approached independently with a car (11 km drive from the visitor center).