Best 20 miler

Doing my first marathon this spring just wondering where and what week to do a 20 mile race , im doing great welsh marathon on the same day as london cheers 

the san domenico 20 is always a brilliantlky organised race......starts at merthyr tydvil usually towards the end of March......it s a tough one as the second half is harder than the first..............but if you can keep it even paced then its a brilliant grounding for the marathon..........

rhyader 20 is good around the same time...........tough first 6 miles going up into the mountains and then an easier 14 afterwards......lovely and scenic

Stafford 20 miler is at the start of March. 

Ashby 20 and Gloucester 20 are personal favorites of mine.

Owl

Another vote for San Domenico here, especially if you are based in Wales. The terrain is likely to be closer to that of the Great Welsh Marathon than some of the other big 20 mile races.  You get a nice tech tshirt at the end of the race too.

This isn't a criticism of San Dom, but just something to keep in mind is that the water stations have cups, not bottles, so you might want to carry some water with you in Camelbak etc. Race weekend this year was really hot for March and I got pretty dehydrated and sick by the end of the race, not a pleasant experience