Hmmmm. My
hometown might make for an interesting HGW, but more for the tactical and strategic side, or SoL, than for some flashy environmental gimmicks or big-name heroes. It's terrain can vary a lot, especially around the outlying areas where the regions hills and valleys become much more noticeable. There's a great deal of ongoing construction in the area; it's one of the US's fastest growing cities, but at the same time, there's little night life outside of the city center. Most of it is quiet suburbs, though the college can be seen as almost a town unto itself.
The mix of terrain and its proximity to the much larger city of Nashville open up some interesting possibilities, as do the relatively large number of open spaces in and around the city, including a few parks and quite a bit of farm and woodland space. However, the population means that open warfare would be difficult to conceal, and large-scale attacks would be problematic. It lends itself well to more subtle Servants fighting skirmishing guerrilla wars and trying to locate enemy Servants and Masters rather than large-scale battles. This is a place for duels in the dark, not bombing campaigns.
Also, one could easily work in the oft-referenced "big one" earthquake we're overdue for. The last time the fault in the area had a big quake, it created a lake and made the Mississippi River flow backwards for a week, so there's that if you want some horrendous natural disaster to be tied to the Grail.
The area probably would buff most US Servants, but definitely Confederate ones. The Lost Cause of the South is a powerful idea here. It would also likely buff most New Testament figures; sometimes it seems like there's a church on every street corner, though there's also the mosque and a Buddhist Temple on the outskirts, if in opposite directions from one another. There's an interesting ethnic mix in the city due to the neighboring state capital and the college, which draws exchange students. Something like 10-20% of the population are college students, giving an interesting angle and age demographic for potential masters being manipulated into some nefarious scheme, and there are quite a few old, large houses that might be home to a magus dynasty in secret, sitting quietly besides more modern homes as if nothing was out of place.
Presumably the city has some decent ley lines, as those are usually in line with geographic features and are associated with growth and prosperity of the community.