555! 4-8 October 2026.

Five Marathons/ half’s or loops,

on Five Islands in Five Days!

Whether you’re chasing your first 10k, an epic half marathon, a walk through island paradise, or the five most south-western marathons in the UK, 555! is your next adventure.

Following a successful soft launch, the 555 proved to be an extraordinary week—accessible, inclusive, and unforgettable. From walking a single island loop at your own pace, to run-walking your first 10k, building up to your first half marathon, or tackling a marathon every day, this event truly has something for everyone.
And with every route set against the breathtaking Isles of Scilly, the views are as rewarding as the journey.

If you can’t join us for the full week—no problem. Choose any day, pick your distance, and take part as a standalone event.

Your 555! Options

5 Marathons • 5 Islands • 5 Days.  Total: 211 km / 131 miles

5 Half Marathons • 5 Islands • 5 Days.  Total: 106 km / 76 miles

5 Island Loops • 5 Islands • 5 Days.  Approx. Total: 55 km / 35 miles

Each distance uses a set number of clearly marked island loops.

Daily Time Limits

Marathons

6 hours 30 minutes, equivalent to 9:15 min/km or 14:45 min/mile

Half Marathons & Single Loops

At least 5 hours 30 minutes to finish

Half marathons: 15 min/km or 25 min/mile

Loopers: 2.5 km/hr or 1.5 mph (perfect for walkers and families)

Event Hub & Support

A dry indoor venue on each island provides the start/finish area

Access to toilets, hot and cold water, and shelter

Runners may leave a kit bag with personal food and fuel at the start point to access between loops

For the most convenient experience throughout the week, we strongly recommend staying on St Mary’s.

Adventure awaits.