I love adventures, so when you say "real adventure", I assume you mean something hard, something well worth the effort.
Taught for a year in Japan.
Found abandoned Mayan temples using Google Earth and then trekked eight days from Cancun to get to them.
Took a three-month trek across the Rocky Mountains.
The last one was the cheapest, since I walked the entire time, and only took one backpack filled with the most minimal of items. If you've never experienced a thunderstorm at 14,000 feet elevation, it will be a hell of an adventure. This weird static field happens, and all your hair stands on end, you hear this weird buzz, and that basically means you have thirty seconds to get as low as possible before hell happens. Absolutely horrifying and amazing.