Probably my favorite trail run in the area (and probably my favorite run overall) is the one shared by Brandwine Creek State Park and Woodlawn Trustees Wildlife Preserve in North Wilmington. One of the trailheads is only about 5 minutes down the road from me, so it's very convenient and close. There are a few different trail heads you could start from but my favorite is to park at the Jewish Community Center on Garden of Eden Rd., just off Concord Pike Rt. 202 in Talleyville. The trail is well marked at the end of the road next to the lot, and you have a few directions to choose from after getting started. You can go left, which is a bit more narrow and technical, which goes south towards Mount Lebanon Rd, you could go straight, which goes downhill, a bit rocky and leads right to the Brandywine River and the Brandywine Creek State Park trail that heads north towards the DE/PA line. If you did that, you could do a nice out and back to Smith's Bridge just over the PA line for a nice 5 miler. But I like to go right just after getting on the trail and stay about a half mile before going left and down towards the creek. I cross a smaller creek and then head back uphill towards Woodlawn Rd...you'll know you're in the right place when the trees clear and you see a horse farm and a road where you have to turn left. You'll go straight until you hit Thompson's Bridge Rd., which I then cross, go past a small gravel parking lot and continue through a small cluster of trees and stay right at the fork and continue downhill, crossing Ramsey Rd. and keep following the trail past another horse farm. One warning about being on these trails is that they are frequently used for horseback riding and mountain biking as well, so it would probably be wise to leave the headphones at home. I've also crossed paths with many a deer and foxes, so be on the lookout for wildlife of all shapes and sizes.
It may all look like private property, but as long as you stay on the marked trail (you'll see signs saying "Wildlife Preserve" and it will usually be roped or fenced off from the private property) I usually keep going north across Beaver Valley Rd. where the trail perimeters cornfields and crosses a few more creeks, going behind the Hi-Point Dairy. There are some great lookout spots on the high parts of the trail before heading down towards the Creek. Eventually I make my way down to the Brandywine where I turn south and head back along the creekside trail. After crossing back over Thompson's Bridge Rd., go about a half mile and just past a small pedestrian bridge, you'll see a trail on the left which will take you back up towards the JCC parking lot. The run in full is just over 8 miles, which may seem like a bit much. You could definitely shorten and/or vary it up by staying on the upper trails or staying down on the creekside trail like I described. Find whatever suits you, but I'm sure you will savor and enjoy it given the beautiful natural surroundings.
Here are some fully marked trail maps to help you along...
Accurate measured route map of the run I described
Brandywine Creek State Park Map
Woodlawn Trustees Trail Map
If you're not familiar with the area, I would keep the map handy, a phone and/or gps or compass and start short to get your bearings. Once you go a few times, you'll find it easier to navigate.
You'll see on the map there are several other parking areas with access to the Woodlawn Trails. One of the larger lots is is at Ramsey Road. Take I95 Exit 8 onto US-202/Concord Pk. toward W Chester/Wilmington. Go 5 miles. Turn left at Beaver Valley Rd. (The big intersection before Brandywine Town Center) Go .3 miles. Turn left at Ramsey Rd and go 0.4 miles. Then turn right to stay on Ramsey Rd. The parking lot will be .8 miles on the right. A gravel road across the street from the parking lot leads to several trails. There is also a trailhead at the back of that parking lot.
This truly is a diamond in the rough of the narrow cramped roads and private property taking up most of the space in the area, so it is a rarity. I would love for others to enjoy the natural beauty of the trails as much as I do. Feel free to drop me a line with any questions or advice...then get out the door and go! Good night and good running.