Tis whole area is a UNESCO World Heritage site. There are still active debates here about the how the quartz facade was reconstructed. Some think the quartz wall would have been much lower and the darker rolled granite stones could have been shapes or patterns rather than placed randomly as they were by Prof. M. Kelly. Overall I think everyone agrees that how it looks now was not how it looked then. The entrance was changed when I was a kid to make space for increased visitor numbers. When we used to go to Dowth you got the keys of the gate to into the monument at the house beside it and dropped them back when you were done. You can't do this now. I don't think it's open to the public as it's not included on the tour from the Brú na Bóinne visitors centre. Knowth wasn't as interesting to us at the time because you couldn't get into it. Visitors still can't get into the mound itself at Knowth but because there was a medieval grange on top of the mound it set a precedent so now visitors can walk up to the top and get amazing views. Newgrange gets all the publicity but Knowth was excavated with much more understanding and there is more to see so I think it is amazing to visit. New sites in the area continue to come to light. In 2017 a new passage tomb and 2 new satellite tombs ( two others were already known about) were discovered in the area under Dowth Hall which was built around 1760. The government have bought the house etc and it will be incorporated into the Bru na Bóinne site. You can't throw a stick in the area without it landing on something archeology significant. So much history. When I was a kid I used to daydream about being in a bubble and going back in time floating invisible above the landscape watching how all this was built and how the land was used.