This is overlooking the St. John's River near Jacksonville, FL. The site is part of the Fort Caroline National Monument. It honors the French explorer, Jean Ribald, who erected a monument near here in 1562. Memorials are an important part of history telling us what was critical in other eras or even what is critical that transcends time and place.
"So Joshua called together the twelve men he had chosen—one from each of the tribes of Israel. He told them, “Go into the middle of the Jordan, in front of the Ark of the lord your God. Each of you must pick up one stone and carry it out on your shoulder—twelve stones in all, one for each of the twelve tribes of Israel. We will use these stones to build a memorial. In the future your children will ask you, ‘What do these stones mean?’ Then you can tell them, ‘They remind us that the Jordan River stopped flowing when the Ark of the lord’s Covenant went across.’ These stones will stand as a memorial among the people of Israel forever.” Joshua 4: 5-7 NLT
Here is another Florida stone this one to honor a Spanish explorer, De Soto.