The South Taconic Trail is a 21.5 mile (34.5 km) hiking trail in the Taconic Mountains of southwest Massachusetts and adjacent New York. After a recent 6.5 mile expansion, the trail now begins and extends from Shagroy Road, south of Rudd Pond Taconic State Park in Millerton, New York, and runs north along the ridgecrest of the southern Taconic Range through the town of Mt. Washington, Mass. and ends east of the Catamount Ski Area on Nicholson Road in Egremont, Massachusetts.

The Newport Cliff Walk is a 3.4 mile path from Memorial Boulevard to Bellevue Avenue. It offers stunning views of both the Newport Mansions and the Atlantic Ocean throughout. The path starts relatively easy as it is smooth and paved but is slowed down significantly in the second half with plenty of rocky terrain. It is a popular tourist attraction and can be crowded in the summer.

The route has a Strava segment, but these can be off by some seconds so time should also be kept with a stopwatch.

A route following the Dorset coastline. From the Devon-Dorset border, via paths, trails etc which keep you closest to the coast, to the Dorset-Hamphire border. Also completing a loop of the Isle of Portland along the way. The route is approximately 100miles with around 17,500ft of ascent. 

Start timings could be important with this as at Lulworth Ranges the gates need to be open and no firing happening. Also to cross the water at Studland the Sandbanks ferry needs to be running.

There are races which happen in this area but none are border-to-border.