I’ve been to 100 countries. I didn't expect to want to return to these 5

I'm often asked: "What is your favorite country to visit?"

For an avid adventurer, it's a confounding question. How to distill culture, vibes, food, scenery, and all the other factors that shape the international travel experience?

Identifying the nations I have explored in depth over multiple visits — popular places like Turkey, Nepal, South Africa and Indonesia — is one measure.  A more novel approach might be to consider the places I expected to visit only once but which surprisingly left me wanting more.

Here are the spots I thought would be "one and done" but that are on my list of return trips.

I was unprepared for the natural beauty of Rwanda. Like many, I traveled to Rwanda for the primate trekking. But the sudden closure of the Burundi border meant I had some extra time.

What a serendipitous gift it was to discover gorgeous tea plantations, a luscious landscape of a thousand hills, and the singing fishermen of Lake Kivu who work at night from tri-hulled boats. 

Rwanda gets kudos for its reconciliation after the 1994 genocide. Across the country there are genocide memorials, which approach its difficult history respectfully and transparently.

The primate trekking is not too shabby, either. I ventured to Volcanoes National Park in search of the golden monkey, a photogenic sub-species found in central Africa's Virunga Mountains. I was hoping for a close-up, but instead got a close encounter. One mischievous monkey found his happy place between my feet.

At a dramatic cliff named the "Edge of the World," I watched the amber sun drift below the horizon on my first day in the Kingdom. The vast, uninterrupted views will be hard to top, I thought.

A few days later I experienced another Saudi superlative while immersed in a