Spring into action with the Phoenix Running & Global Marathon Challenges' Ten in Ten and Twelve in Twelve series, returning for 2027 from March 20th through Easter Monday. This year’s edition promises to be an even grander celebration of endurance running along the picturesque River Thames in Walton on Thames. Participants have a unique opportunity to double down at half marathon distance by completing two back-to-back half marathons each day for either ten or twelve consecutive days, culminating in 20 or 24 races. The series offers an array of distances from 5km to ultra-marathon lengths, allowing runners to customize their challenge according to personal preference and ability. The race takes place on a carefully measured and certified route along the River Thames that winds through tranquil landscapes and bustling urban scenes alike. Each day’s run is timed over five to nine hours, giving participants ample time to explore different paces and distances while enjoying the scenic beauty of the riverbank. Early starts are available for those who wish to extend their running window. The event's central hub at Walton on Thames offers a variety of amenities, including a "runners breakfast" served right next to the start/finish line by the Weir Pub, ensuring runners have plenty of energy before heading out onto the course. Accommodation is readily available in nearby areas for those traveling from afar. One of the highlights of this event is its distinctive medal system known as “Discovering the 10 Lanterns” or "The 12 Lanterns" for participants running twelve days. Each day, runners earn a unique Phoenix Running lantern-shaped medal with an inlaid colored glass effect that symbolizes different qualities such as fortitude and perseverance. Completing all ten or twelve days earns you a full set of these stunning, multicolored medals. In addition to the bling, finishers receive a bespoke GMC Finisher’s t-shirt at the conclusion of their final race day. For those who opt for the no-medal/no-t-shirt entry option, shirts can still be purchased after registration. The series is open to all levels of runners; whether you’re aiming to complete one lap or several over ten days, everyone is celebrated as a winner in this inclusive event. Join us and experience an unparalleled blend of scenic routes, supportive community spirit, and the thrill of pushing your limits along the Thames Path. With early bird discounts available until April 30th, now's the time to secure your spot for the biggest multi-day running series in the UK. This year’s Ten in Ten & Twelve in Twelve promises an unforgettable journey of personal discovery and camaraderie among fellow runners, all set against the backdrop of springtime London.
Races Offered
Affiliated
Mar 20, 2027
straighten
Distance —
Affiliated
terrain
Type —
Running
timer
08:30
sell
£350.00
Twenty in Ten (DOUBLE Half Marathons) Affiliated
Mar 20, 2027
straighten
Distance —
Twenty in Ten (DOUBLE Half Marathons) Affiliated
terrain
Type —
Running
timer
08:30
sell
£499.00
Twenty in Ten (DOUBLE Half Marathons) Unattached
Mar 20, 2027
straighten
Distance —
Twenty in Ten (DOUBLE Half Marathons) Unattached
terrain
Type —
Running
timer
08:30
sell
£539.00
Unattached
Mar 20, 2027
straighten
Distance —
Unattached
terrain
Type —
Running
timer
08:30
sell
£370.00
Weather History
These values represent the 3-year monthly averages for March in Walton on Thames.
thermostatTemperature
4.4° / 11.5°
wb_sunnyFeels like
0.6° / 7.3°
light_mode
Avg sunshine hours
6h 26m
water_drop
Avg rainfall
2.3 mm
ac_unit
Avg snowfall
0.1 cm
air
Avg wind speed
14.7 km/h (Gentle breeze)
opacity
Sweat loss rate
Low
terrain
Course conditions
Firm and slightly soft
sunny
Max UV Index
Low (2.8)
humidity_mid
Humidity
81.3%
wb_twilight
Sunrise
07:12
nightlight
Sunset
19:07
About Walton on Thames
Learn more about the host city, Walton on Thames.
Walton-on-Thames, known locally as Walton, is a market town on the south bank of the Thames in northwest Surrey, England. It is in the Borough of Elmbridge, about 15 mi (24 km) southwest of central London. Walton forms part of the Greater London Built-up Area, and is served by a wide range of transport links. According to the 2011 Census, the town has a total population of 22,834. The town itself consists mostly of suburban streets, with a historic town centre of Celtic origin. It is one of the largest towns in Elmbridge, alongside Weybridge.