This one's for the real heads. When you've graduated past the classic Boston and Arizona, it's time to dig deep into the Birkenstock catalogue...

Montana looks like someone you'd cobble together when the country club won't let you in wearing sandals. It's quirky looks are matched only by the comfort—we wouldn't expect anything less.

One of the unique features on the Montana (and there's plenty) is the no-sew construction. Inspecting them will reveal there's not a single stitch on these uppers. Instead, simple rivets hold the shoe together at key points.