This is the Swedish Nyckelharpa. The origin of this instrument dates back to around 1350 or so. Sort of a distant cousin of the Hurdy Gurdy which predates it by a couple of hundred years. Basically, it's the push button fiddle of medieval times. I used this instrument extensively in the score for the movie THE WITCH.
It has three melodic strings, one low drone, and quite a few resonating strings, which gives it a reverberant sound. In this recording, I didn't add any reverb at all. It's just the sound of the instrument.
There is also an OctavHarpa used, which is much larger, and sounds an octave lower.
Also there is an ancient reed instrument (which dates back to biblical times) called the Armenian Duduk. I added a lower octave.