The santûr is a very popular court music instrument in Iran but also in Turkey and Iraq. It's frequently used in the classical Persian music but it's also a traditional Indian instrument.
The name of this middle eastern instrument comes from the Greek psalterion. Just like the qanûn - whom it is close related to - the santur arrived in Europe during the Moorish occupation of Spain. From then on it started to play an important role in the music of the Middle Ages. Strings are beaten by two drumsticks.
Santours are tuned according to the dastgah (Iranian) or maqam (Iraqi) modi. A traditional Iranian santur has 9 high cords divided into octaves and one row of 9 bass cords tuned an octave lower. The Arabic and Turkish qanun has little brass handles abling to raise the tone by one comma (8 commas=1 semi-tone) just as the qa'nûn.
Nowadays it still plays an important role in the music of the balkan countries, especially with the Hungarian and Romanian gypsies where it is known under the name cymbalon.
The strings of this instrument are hammered with two sticks. On this principle the piano and his relatives were build. So we could say the santur is the grandfather of the piano.