2027 Great Welsh Marathon - Oct 17

The organisers market the Great Welsh as one of the flattest, fastest marathons in the UK. Its established Pembrey course had only modest total climb of roughly 110m and a maximum elevation around 18m; for 2027 the event moves to a brand-new course elsewhere in Carmarthenshire (exact route confirmed closer to race day), again aimed at first-timers and PB chasers. +110m elevation