In California, at Disneyland, the Mickey Mouse head Ferris Wheel clearly lets you know that you are at Disneyland. It's iconic. At Disney World, there are other iconic elements you can't miss.
Sometimes, there are buildings that identify where you are at. You see a picture and you know exactly where it is and you can remember the time you visited. At Disney World, there are several key locations, buildings, structures, and more that define the parks as individual locations, as well as others that simply say, "yes, you are at Disney World."
For me nothing says you have arrived more than the Walt Disney World - Where Dreams Come True sign. Turning off of I-4 and making the right toward Disney World you can't miss it. It welcomes you and you realize that you have reached Disney property (until Ron Desantis finds a way to change that).
Once inside there are other icon locations that just say, Disney.
The Monorail.
You don't need to be in a park to see the monorail shuttling guests from Magic Kingdom to EPCOT. The rail runs along the traffic routes and is pretty hard to miss unless you are driving and keeping your eye on the road.
The monorail towers over roads but once you see it, you just want to ride it. The Skyliner is also starting to get that same iconic feel to it but it is still too "new". Regardless, you see it and you know where you are.
The Hollywood Tower of Terror
It is the most recognizable site from the roads around Disney parks and easily seen. The pinkish facade is very recognizable and is a landmark for Hollywood Studios.
Tree of Life
You can't see it from the roads around Disney World. You can't see it from the parking lot but once you crest the top of the hill after passing the entry gate, it stands before you and what is great about this is that the Tree of Life changes as you walk around it or under it. The carvings in the tree don't repeat and you could spend all day trying to see all of the animals represented.
Spaceship Earth
You don't have to be in EPCOT to see Spaceship Earth - the big EPCOT Ball. While you can see it from the roads around the parks, the EPCOT ball is one of the most recognized icons in te world. You see a picture and you know where it is and what it is. You just may not know what is inside of it.
Spaceship Earth is the EPCOT land mark that identifies the park and has become synonymous with Disney as much as Cinderella's Castle.
Cinderella's Castle
Nothing says Disney World like Cinderella's Castle. It is the face of Disney in Orlando. From nearby hotels you can see the castle in the distance. Take the monorail to M.K. and you see it over the train station, from the ferry in front or behind you.
The nightly fireworks show at M.K. go off behind and above the iconic castle. You can walk under it, around it, and it is the most photographed Disney location by far. At M.K. the castle is the center of the entire park and from every area of Magic Kindgom you can see it.