I stopped by the International Friendship Park but no one was there. The park, ironically, is just over the border fence with Mexico in Imperial Beach, San Diego, California. Just over the fence, which most could easily swim around, is the Monumental Plaza de Toros de Tijuana, or the Bullring by the Sea. According to their website Access to Friendship Park within the US federal patrol zone is available weekly on Saturdays and Sundays from 10 am to 2 pm. The US side is supervised by Border Patrol agents and visitors should be prepared to show ID! (Sounds friendly! And internationally so!)
An image from the park’s website shows the “binational meeting place” where, we are told, it is illegal to pass items between countries.