The mark of a good lesson is when you want to reuse it.
I have taken students outside for their FIRST lesson in Object-Oriented Programming since my first year of tertiary teaching in 2001.
I did this last year & posted about it here: https://elketeaches.wordpress.com/2015/04/26/outside-oop/
I did this again today BUT I added a NEW element. In a group, students had to create a poster that describes some of the basic OOP concepts they learned on our walk. Students got to collaborate, think and design together. There was some arguing and my class was loud; everyone loved it! To prove that it was not a difficult task I also attempted to draw some OOP and PokemonGO images on the whiteboard.
Now we have something interesting and student-created on our classroom walls.