Brú na Bóinne: Far more of the large stones surrounding Knowth Mound are carved with decorations than the ones at Newgrange. There was a Native American scholar on our tour who was interested to note the comparisons between these designs and those made by his own ancestors. The projecting concrete ledge was built in modern times to protect the stones. One of them is currently behind plexiglass as a test to see whether similarly covering the rest would better preserve the engravings.