When people say “adventure” it brings up connotations of super long journeys over unexplored lands, mountains and oceans but more and more people are challenging that thought. There’s a movement of micro adventures like those Alistair humphrys advocates and I’m completely on that band waggon. That’s not taking anything away from those who do those kind of expeditions btw!
I’ve recently been inspired by the awesome adventures showcased in the Banff Mountain Film festival. although these were mammoth feats, of some folk who have the time and energy to do that, I feel that your adventure is as big as you make it. 

Meaning, an adventure could be going off for a walk exploring a well worn path that you’ve never been on, or it could be camping out in the wild. 

I like to do a mini adventure on my long runs and cycles. You might just class those as going out for training but given I’m cycling 40+km and running 20+km you can go pretty far and see lots on these training days. 

A-B routes feel the most adventurous as well as those that go over hills and mountains. Yet, a 10km run around a new city can also be an adventure. You just have to have that mindset. 

This is one of the reasons I run and ride so much. Because it brings out the adventurous side in me. 

A lunchtime adventure up a volcano

Weekend escape to the hills

A long ride to work via a different path