The linked Achill event is a half marathon and 10K
The current Achill site publishes half-marathon and 10K results, maps and participant information. Those pages belong to the shorter event on the island. They should not be used to assign a full-marathon start, cutoff, fee or collection appointment to this listing.
The half marathon starts and finishes in Keel and follows a circular route with hills and coastal exposure. Those are facts about that half marathon, not proof that running it twice would constitute an officially organized full marathon. A back-to-back event would also need an explicit schedule and entry for each separate day.
The organizer’s first-Saturday-of-July pattern does not confirm the date of a different event with a similar name. Verify the exact race name and organizer on an entry confirmation before planning travel. If you intended to enter the half marathon, use its official site and its own current instructions rather than this historical full-distance listing.
For an actual back-to-back marathon goal, check whether one or both days are included, whether each course is measured, and how support, cutoffs and recovery logistics operate between days. Choose that challenge only after comparing it with your recent experience. Until an active Achill full-distance announcement is available, select another confirmed marathon if you need a firm training deadline.
Last-known race profile
These details identify the race page; they do not establish the next edition's operations. The previous race date does not establish the next edition. Wait for the organizer’s announcement before committing to a race-day schedule.