Behind the scenes of The Lost World: Jurassic Park (1997). To shoot the scenes where the second trailer was hanging vertically over the cliff, the production built a cliff facade on a parking garage and hung the trailer on a crane.

From set designer/art director Lauren Polizzi’s website:

“When it came time to build and film the scene where the trailer is hanging over the cliff edge, the question of how to do it – and where – was raised. Steven originally wanted to film this on stage, naturally, but the overhead grid wasn’t A) strong enough to hold the trailers or B) tall enough to film the scene the way he wanted to. SPFX Coordinator, Michael Lantieri, and others explored cutting a hole in the roof of the stage and hanging the trailer on a cable from a crane outside. This was quickly proven costly and inefficient. I somewhat kiddingly suggested we hang it over the edge of an adjacent Universal office building to our stage. The building consisted of offices on the lower floors and a parking structure above them. This turned out to be the solution! The building height was good for what we needed, the structure could hold the weight of both the trailer and the counterweight needed for it on top of the building, and the tenants said ok to having their windows obstructed for the time we needed. An added advantage was that there was another parking structure right across the way which could be used as an alternate shooting platform on different levels.

So we built a section of the cliff over the face of the facade and hung the trailer over the edge. You just never know what’s going to be possible on a film!”