Hello,
One thing that has always interested me is freedom of movement agreements between nations. We all know about the EU freedom of movement and the very similar EEA and Swiss agreements that go with it. However, I would like to learn more about other freedom of movement agreements your country(ies) may have that are less known and not discussed as much and any unique benefits that you get from it not covered by the EU (if it's between EU / EEA / Swiss countries). Some obscure freedom of movement regimes I know of are Armenia + Belarus and North Korea + Kyrgyzstan.