Mount Longonot is an inactive volcano located just south of Lake Naivasha. This trail starts at the main gate parking lot, goes up to the caldera, around, and back down to the parking. Along the way, you will have scenic views looking out at Lake Naivasha and the crater of the volcano. On the way, you may spot some animals such as buffalo, monkeys, zebras, and different game. This trail starts at 2,143 meters (7,031 feet), and the summit is at 2780 meters (9121 feet).

There is a Strava segment for this route.

https://www.nationaltrail.co.uk/en_GB/trails/peddars-way-and-norfolk-coast-path/

In overview, the route loops round the high features around the edge of the beautiful Black Mountains in South East Wales. The route follows well established routes and clear landmarks following a clearly identifiable high ground. On clear days, views range from across the Brecon Beacons to mid-Wales and the Cotswolds.

https://www.walkingenglishman.com/ldp/LDP/Q/quantockgreenway.pdf

The Quantock Greenway is a footpath within the Quantock Hills in Somerset which opened in 2001.The route of the path follows a figure of 8 centred on Triscombe, the northern loop taking in Crowcombe and Holford is 20 miles (31 km), the southern loop to Broomfield is 18 miles (29 km). 

Circle well marked trail around Spa town Harrogate North Yorkshire,UK

"Prenj's 11" is a loop traversing all Prenj's peaks higher than 2000 m. It was long considered impossible to climb all 11 of them in one day so it's quite an undertaking. It's not the length that makes it hard as it's really not that long. It's not even the vertical gain that creates problems, which is massive considering the length. It's the terrain that is brutal together with the fact that most of the route is unmarked and off trails what makes it challenging.