If I understand correctly, you want both the Eiffel Tower AND your subject in focus? To do this, you need to do some things to widen your dof to infinity.
There are four main factors that contribute to dof: (I know many here know this but their are many that don't, so bear with me)
1. The aperture....shoot at f11 rather than f5.6 or f4...this will help widen your dof.
2. Distance to your subject ... The closer you are to the subject, the narrower the dof. Move further away and your dof will widen.
3. The focal length of your lens...an 85mm lens will have a narrower dof than a 24mm. So as someone else said, shoot wide to increase your dof. 24mm or wider in this case.
4. Your sensor size...a full frame sensor will give you a narrower dof compared to a crop sensor.
So for the tower shot, shoot at f11 and use a 24mm lens...this your starting point. Then, just understand that the closer you get to the subject, the narrower your dof will become, and the more likely the tower will be out of focus. The problem, is that to get the "Godzilla" effect as you describe, you need to be close to the subject, so that they appear to be as big or bigger than the tower..... This is why you need to shoot at 24mm or wider
Omar...as someone else posted, spend 5 minutes playing around with the settings on the following website and you'll learn a lot about the 4 factors that control dof....important stuff.
http://www.dofmaster.com/dofjs.html