During my visit at the world-renowned museum, we were treated to a private tour by an astute gentleman who had worked there for 12 years and then started his own business. How wonderful to experience the Louvre with an expert by your side to make the visit more "interactive."
In this photo, look closely at stone blocks. They are on exhibit when you first enter the museum and were unearthed when builders were working on the land where the exhibit stands. Do you see the hearts engraved on the stone (upper right side of the photo and bottom center)? That's a "brand" mark. Back in olden times, the suppliers of the block bricks would carve a simple symbol - in this case, a heart - into the stone, as a way of identifying their business.
I wish I could have taken more!
But what if I were left behind at the Louvre? I wouldn't have minded sleeping under the Mona Lisa and staying another day ...