Green-screen technology can put actors anywhere on the globe, or outside of it, and make the scene at least somewhat convincing. The more authentic method of building a world for audiences, however, is actually, physically building that world--with an elaborate film set. In some cases, these worlds live on long after the cameras have stopped rolling.
Once James Cameron finished using the enormous scale model of the Titanic he'd built for exteriors on what was then the most expensive movie of all time, he sold off parts of the ship for scrap metal. According to online guide to uncommon travel spots Atlas Obscura, though, other film sets have had interesting afterlives. Some have become premier tourist destinations like New Zealand's "Hobbiton," where Lord of the Rings was shot, and Tunisia's Popeye Village, home of the 1980 Robert Altman bomb, Popeye. Some sets from Star Wars, meanwhile, have gone on to different fates. While Tunisians have converted Tatooine into a hotel, Mos Espa stands exactly as George Lucas's crew left it. Similarly, savvy Texans can remember the Alamo any time.
Take a look at more film sets in the slides above, and go to Atlas Obscura to read more about what's become of them since the film crews left town.