A ~70km loop in the Sawtooth Mountains near Stanley, submitted by Garrick Arends:

Starts at the northenmost part of the Rock Creek Trail in Olney Maryland, the address is roughly 19801-19813 Muncaster Rd, Derwood, MD 20855 (39.182411, -77.113771). This will follow the Rock Creek Trail system all of the way south until we hit the DC line at (38.986208, -77.053093). When you hit the DC line we follow the NPS's Western Ridge Trail in Rock Creek Park until Bluff Bridge at (38.936740, -77.048038) where the trail turns into Rock Creek Trail.

A 65km beach run (not on the highway) on the west coast of Nambia.  End points are the De Duine Hotel in Hentiesbaai and the  Strand Hotel (beach hotel) in Swakopmund. 

A popular short hill climb, 4.5 miles TH-to-TH, with 1600' of elevation gain.  The round trip has a Strava segment.

https://www.atlantatrails.com/hiking-trails/yonah-mountain-hiking-trail/

The Quehanna Trail is a long-distance loop trail near Pennfield Pennsylvania that passes through the Moshannon and Elk State Forests which offer some of the most wild and beautiful country in Pennsylvania. The trail is marked with orange blazes and the most current maps have it at 70.3 miles. Its western end and primary start/end point is located in Parker Dam State Park.

The Lancashire coastline has a variety of landscapes from the distinctive limestone scenery of Arnside and Silverdale, saltmarshes and agricultural land and the seaside resorts of Morecambe and Blackpool and the Fylde coast. Lancaster and Carnforth are passed en route. There are major river estuaries of the Lune, Wyre and Ribble with much bird life.