This week on The Travel Detective: It's between the mountains and the sea in the heart of aviation country in the Pacific Northwest. Imagine 2,000 square miles of farmlands, rivers, historic cities and driftwood coastlines, and few people even know about it. I share with you some of my hidden gems of Seattle NorthCountry. That's our cover story.

Plus, there have been major breakthroughs over the years to make planes more environmentallyfriendly. But, Correspondent Scott McCartney reveals that many hurdles remain to get to an electric future in commercial air travel. And then, Correspondent Arne Weissmann explores an exceptional World Heritage Site in the Kingdom of Saudi Arabia. A genuine old town dating back almost a millennium.

All this and more on the next edition of The Travel Detective on PBS. Check your local listings.