The Drive-In the boys crash their ship into was here but closed down after the big screen burnt down in 1989 and is now a shopping center.
Much of Explorer's was filmed in Petaluma including the scene where Ethan Hawke's character floats in a bubble up to Lori Swanson's window here on D Street.
This is where the ship splashes down and the jetty nearby is where the boys climb out of the river.
This is where River Phoenix's Wolfgang lands when testing out the flying bubble, on a ridge line, next to a large old oak tree.