Two Cities, Two Countries, Common Ground - The New York Times
Initial Point of Boundary Between U.S. and Mexico - Wikipedia
Your Guide to Crossing the San Ysidro Border
Tijuana, Mexico, Map, History, & Facts
Cut in two: travels along the US-Mexico border – a photo essay
The development of tunnels along the US-Mexico border •
Photos show border walls dividing the U.S. and Mexico
What's a Border to Do?
Friendship Park – San Diego, California - Atlas Obscura
How violent American vigilantes at the border led to Trump's wall