Connecting all 15 peaks over 3000 feet in Wales: https://www.welsh3000s.co.uk/
Time is kept from the first summit to the last.
"The Welsh 3000s Challenge
In order to complete the Welsh 3000s Challenge you are required to have been at the top of all 15 of the mountains over 3000 ft in Wales within the space of 24 hours, without using any form of transport.
The length is about 24 miles, but the walks to the start point and down from the finish point can take it to over 30 miles in total.
The walk is also known as "The 14 Peaks" (although there are officially 15 peaks, or possibly 16)."
The FKT was apparently held from 1988-2019 by Colin Donnelly, 4h19m, which was about 10min under the previous time of Joss Naylor.