Great trail network regions in the Mid Atlantic (US)?

cross-posted from: https://lemm.ee/post/53136416

I've done the vast majority of my hiking in north-central PA, and even after moving away I keep going back because of the incredible trail network. It's always possible to put together an worthwhile loop of any distance you want, from 2-200 miles (attached screenshot of my day hikes in the area as evidence).

I'd like to break my pattern and explore more areas, particularly Virginia. Any specific forest/area in VA (or the rest of the Mid Atlantic) with a comparably dense and extensive trail network?