One of the great features introduced back in LR2 was the Camera Correction panel in the Develop module. Lenses have built in distortions based upon the design of their optics. You’ve seen the effect when the tall buildings in your pictures seem to either lean way back away from the camera or tilt to one side in part of the picture while appearing vertical elsewhere. Some lenses get “curvey” out towards the outer edges of the images, some cause vignetting (darkness around the corners) based on how light is processed as it passes through the various pieces of glass. Because these flaws can be modeled and profiled, the Adobe software designers can correct the image to display things as they “should be”. Here is a perfectly average picture of the U.S. Naval Academy chapel dome (GO NAVY-BEAT ARMY).
I applied a little darkening to the sky and pushed up the blacks to make it a little crisper, but it still remains a really average shot. 
Since not all lenses are modeled yet, they included manual controls which permit you to adjust the various characteristics of your image.
But what if you don’t want your image to be normal looking? Well, LR lets you use the Lens Correction controls for evil as well as for good…
You can stretch the building vertically
You can stretch it horizontally as well
You can squish it inwards
And you can create your own virtual “fish-eye” lens effect. 
These effects work on people as well, but I don’t recommend stretching it horizontally on a spouse or significant other. You can combine multiple effects until you find something interesting. Best of all, as with all LR adjustments, all of these are completely reversible. So straighten out your buildings where you can, but have fun and play around with your images.