There is nothing quite like making amazing and unique discoveries in the world, whether new or old. Archeologists find a wide variety of different things in the earth that give us insights into past civilizations, how people used to live, what creatures used to roam here, and more. However, there are some artifacts that are found that simply produce more questions than they answer. Some items are found that simply no one can explain where they came from, even what they are and more. Here are 18 items that have been found on earth that simply can’t be explained, and number 15 is particularly interesting.