Hi K: Unlike traditional microwaves located on a counter or over-the-range that feature a door that swings open, some manufacturers (like Sharp and Bosch, for example) offer microwaves that open like a drawer and can be used under a counter or in an island.

Here is a link to some examples to help you out: http://www.houzz.com/photos/products/query/drawer-microwaves/nqrwns

Good luck with your next home project!