This was my second trip to Antietam but on my first trip I was amazed by the Sunken Road. My first contact with a sunken road was at Shiloh and once you've been to both you know there is truly only one sunken road. Shiloh's sunken road would barely protect an ankle from a bullet while Antietam's is, with some variations, a pretty extensive trench.
To truly understand this area though you have to walk the ground that the Union attacked over. The tower does help show the undulating ground but until you wander across those fields you really don't have an appreciation for the rolling ground. That being said though I lack good pictures to show the rolling ground, just one of those things you kinda need to walk to get a feel for. I have included a photo taken from the tower that does shows the rolling ground somewhat.
This first picture was taken from outside the observation deck at the VC, looking east-southeast towards the tower. The Union attack came from the left side of the picture.
Here's two views looking back towards the VC from in the sunken road. Even these don't really convey the depth of the road. This monument is also the one that appears prominently in my sunrise pictures post of a few days ago. The second photo I included just because I like how much is in the shot. The 132nd Pennsylvania is in the foreground with the 14th Connecticut and New York monuments also visible. Additionally the cannon just south of the VC are visible.
And here's a shot looking mostly north taken from the tower. The rolling terrain can be made out somewhat.