Signal Mountain did not play too much of a role in the siege of Chattanooga. It was a Union signal post. Today it offers great views along the Tennessee River. This first picture shows the Tennessee River north of Chattanooga through what is called the Grand Canyon of the Tennessee River. The Confederates did have pickets along the river at various points to halt river supply traffic for the Union army in Chattanooga.
And the view into Chattanooga. It was a little too foggy that day to see much of the town but a few other landmarks are visible which will help you locate other things. The fog shrouded mountain in the distance on the right side is Lookout Mountain. In the foreground you can see Williams Island. This puts the city at the left center of the picture, and you can kinda make it out anyway but those two landmarks make it much clearer. I'd love to get on Signal Mountain sometime when it wasn't so foggy but the only times I've had the free time to go there it has been foggy, or rainy.