Unsolved Mysteries of History by Paul Aron is a great collection of stories of mysterious events, objects and happenstances throughout history. Some of the mysteries include: a discussion of the Neanderthals and their place in the human evolutionary tree, the construction of stonehenge, the construction of the pyramids of Giza, the Trojan war, the resurrection of Christ, the Nazca lines, the statues of Easter Island, Joan of Arc's sign and many more.
Aron definitely has his opinion surrounding some of the mysteries presented, especially the resurrection of Christ. He believes that the resurrection never took place. He cites a great deal of evidence to support the notion. This may prove disturbing for some readers; however, I found it quite fascinating. He also makes guesses about the etiology of the collapse of the Mayan Civilization.
This is a great collection of concise stories of unexplained events throughout human history. Very fascinating.