As most North Americans on this forum probably know, there are two international parks on the US/Canada border: The Peace Arch in Washington State/British Columbia and the Peace Garden in North Dakota/Manitoba. The system for visiting both is the same: There is no border check to
enter either park; however, you have to go through Customs to leave, even if you are returning to the same side of the border you entered the park on.
What I didn't know until recently was that a similar park was built on the US/Mexico border within walking distance of the Pacific Ocean: Friendship Park.
http://www.friendshippark.org/
It is apparent to me that when this park was built in 1971, it was intended to be similar in nature to the Peace Arch and Peace Garden. Pat Nixon was at the dedication and personally said, "I hope there won't be a fence here much longer". Her staff cut open the chain link fence during the ceremony so she could cross into Mexico....
Of course, free movement within Friendship Park never came to be. The chain link fence of 1971 is now an 18 foot wall, and access to the US side is limited even for US citizens.
So, my WI for the day is: What if the US and Mexico could have agreed on making Friendship Park "neutral" in the same sense that the Peace Arch and Peace Garden are?
I admit one obstacle to this is that the Mexican side is in an urban area (Tijuana) and it may be possible (though I don't know) that many Mexican citizens may lack papers and thus not be able to leave the park if they enter; this could get disruptive. From the US point of view, all it would take is setting up an additional Customs station at the US entrance road to the park.