This is a popular trail located at Merrill Creek Reservoir.  The trail begins near the Visitor Center parking lot. Follow the black trail markers for the perimeter trail.  If running clockwise the first part of the trail is very runnable and smooth.  Once you start making the turn to head North around the lower end of the lake you'll head into the woods and single track.  The last few miles are a lot tougher as they are full of rocks and big tree roots.

Starting in St Bees, it weaves for around 185 miles (approx 28,000ft ascent) through the Lake District, Yorkshire Dales and North York Moors National Parks, to the coast again, at Robin Hood’s Bay.

https://ldwa.org.uk/ldp/members/show_path.php?path_name=Coast+to+Coast+%28Wainwright%29

Very nice trail from a parking lot besides the cable car (towing device) to the top of the Kralicky Sneznik. Going up - First part is mainly uphill across meadow and slope. Mid section is a very panoramatical flat and totally runable for everyone. The last part is most interesting. You start climbing to the summit on a very rocky terrain. Going down - The first part is identical to the part where you climbed up, but from approx. half of descent the terrain changest to asphalt road that will lead you to the parking lot.