Mawsynmar is located in the southern slopes of khasi hills (meghalaya) at a height of 1500 metre above the sea level and it receives the highest rainfall because
This place is enclosed by hills on three sides .
The rilief feature give this place a funnel shaped location .
The Bay of Bengal branch of monsoons is trapped in these hills .
These winds try to get out of it .
These are forced to rise again and again resulting in heavy rainfall