This is because they were in Las Vegas, for instnace, where the Sphinx and Pyramid in your screenshot is is where The Luxor Hotel is

The other landmarks can also be found in Vegas as mentioned in this link

it is mentioned in the movie that the group needed to go to Vegas in order to get fuel to go for the trip to Alaska where it was thought to be Infection free.

obviously these are only replicas of the real things and for the purpose of the movie production, are replicas of the replicas

This is because they were in Las Vegas, for instance, where the Sphinx and Pyramid in your screenshot is where The Luxor Hotel is.

The other landmarks can also be found in Vegas as mentioned in this website about Las Vegas strip

It is mentioned in the movie that the group needed to go to Vegas in order to get fuel to go for the trip to Alaska where it was thought to be Infection free.

Obviously these are only replicas of the real things and for the purpose of the movie production, are replicas of the replicas.