Edwin B.
Yelp
The UN branch in Geneva may carry out governmental and diplomatic work, but it's much like any other office building. People work here and some meetings are off-limits so the admittedly short tour isn't super involved and won't take you to too many places, but it is worth a visit.
I really just wanted to write this review because our tour guide looked exactly like a slightly German John Oliver. He was an odd mix of enthused and monotone but he was informative enough and he spoke fluently - in multiple languages. We spent at least 30 minutes in one room overlooking one of the central, cylindrical meeting rooms before moving on to the next one. He gave us a brief overview of the UN mission and took us to see a real conference, albeit with no audio or context. From this, we were whisked to the old, original building where the previous League of Nations was established. After seeing the original architecture and the original, refurbished meeting room, the tour ends and you are escorted back to the main lobby.
No wandering solo or away from your group or a security guard will pick you up and kick you out, supposedly.