1- Damascus Steel
Damascus steel is represented in “Game of Thrones” as Valerian Steel. Both materials are stronger and more resilient than normal blades. Legends once told of Damascus steel being able to split a hair, easily slice other swords in half, and cut through rifle barrels.
The real Damascus steel swords have a pattern of banding on them that looks like flowing water. They are named after Syria’s capital city, one of the oldest inhabited cities in the world, but no one actually knows if the steel was forged there.
In the 1700s, the knowledge of how to make Damascus steel was lost.
2- Stradivarius Violins
The sheer sophistication of the technology wielded by the ancient Greeks and Romans is often quite astonishing, especially when it came to medicine. Among other things, the Greeks were known to treat the bereaved with Nepenthe, a primitive anti-depressant that was known for its ability to “chase away sorrow.” The drug is frequently mentioned in Greek literature like Homer’s Odyssey. Some claim that it might be fictional, but others have argued that the drug was real and used widely in ancient Greece. Nepenthe was said to have originated in Egypt, and its effects as “a drug of forgetfulness” have led many to compare it to opium or laudanum.
Lost technologies aren’t always the result of too much secrecy or poor record keeping—sometimes nature just doesn’t cooperate. This was the case with Silphium, an herbal wonder drug that the Romans used as one of the earliest forms of birth control. It was based on the fruit of a particular genus of the fennel plant, a flowering herb that only grew along a certain shoreline in modern day Libya. The heart-shaped fruit of the Silphium plant was known to be something of a cure-all, and was used to treat warts, fever, indigestion and a whole host of other ailments. But it was Silphium’s powers as a contraceptive that made it one of the most valuable substances in the Roman world, to the point that the plant appears on several different pieces of ancient Roman currency. Women would drink Silphium juice every few weeks, and this would be enough to prevent pregnancy. Using the herb would even terminate an existing pregnancy if used correctly, which would make Silphium one of the earliest methods of abortion.
5- Flexible Glass
The Lycurgus Cup is an Ancient Roman goblet kicking around at the Smithsonian. You might wonder what could possibly be so technologically advanced about a cup (does it shimmy over to the fridge and fill itself with beer?). Scientists didn’t notice anything special about it either, until they held it up to the light. You see, it looks green when lit from the front , But when lit from behind, it turns a demonic red.