Subduction zones are often characterized by chains of volcanic activity that form on the over-riding plate.
The Aleutian Arc extending off of Alaska to the west consists of more than 300 individual volcanic islands which formed as a result of the North American Plate subducting beneath the Pacific Plate. It's subducting at an angle of almost 45 degrees!
The Kuril-Kamchatka Trench, where the enourmous Pacific Plate subducts beneath the tiny Okhotsk Plate gave rise to a great deal of arc volcanism.
The many islands of Indonesia are a result of the Australian Plate subducting beneath the Eurasian Plate at the Java and Sunda trenches.