Santoor
Origin: Persia
The name means "one hundred strings" in Persian.Almost 100 steel strings laid on the trapezoidal resonance box, resemble the opened piano. It is played by hitting the strings with the special-shaped mezrab. Beautiful translucent sounds.
The sounds actually have the healing effects, the ancient Persian and Indian seemed to use it for music therapy.
No clear idea of when exactly this instrument was invented, though it showed up in the 10th century Persian poem. then spread to India, Mongol, China, Korea and Europe, modified to suit the land and became their traditional instruments.
Santoor is believed to be the first instrument which used "Paired Strings" (using multiple strings to make one sound). It makes the bigger sounds and longer resonance, very common method used for the guitar, piano, etc. these days. But, when you think about it, somebody who didn't have a tuner or any other tools invented this method - no doubt he/she is a geniuse!!