The Schengen area formed about 20 years ago, so depending on exactly when that was, you may have encountered the freshly opened border.<p>Oddly, there are some places with no real controls but where it is <i>not</i> legal to simply cross. Some of the US&#x2F;Canada border is like that. You can just wander across in certain places, but you&#x27;re required to present yourself to an immigration official if you do.