Billown Circuit

Billown Circuit at a glance

Location

Castletown, Isle of Man

Type

public road circuit

Length

6.84 km (4.25 mi)

Turns

14

Direction

counter-clockwise

Surface

asphalt

Opened

1955

Owner

Isle of Man Government (public roads); organised by the Southern 100 Road Races Committee

Address

Public roads around Castletown, starting and finishing on the Castletown Bypass (A5)

Website

southern100.com

Track map and layout

The Billown Circuit is a 4.25-mile (6.84km) roughly triangular lap of public roads around Castletown in the south of the Isle of Man, raced counter-clockwise using the A5 New Castletown Road bypass as start and finish with the A28 and other local roads completing the loop. From the start it runs flat out to Ballakeighan, a sharp right-hander taken in low gear, then through the fast Iron Gate right-hander, the Ballabeg hairpin and a run past Ballawhetstone and Williams Corner. Billown Dip and the Cross Fourways hairpin lead into the tight, wall-lined Church Bends, a natural chicane through the village, before a final run past Stadium Bend back to the finish. With stone walls and hedges lining most of the lap and few run-off areas, it rewards precision as much as raw speed, and closely-matched top riders regularly lap in the low 2-minute range at well over 110mph average.

Named corners and sections

• Ballakeighan. A sharp right-hander taken in first or second gear at the end of the opening flat-out run from the start.
• Iron Gate. A fast, demanding right-hand bend regarded as one of the circuit's more intimidating corners.
• Church Bends. A tight natural chicane through the village, bordered closely by stone walls.
• Cross Fourways. A hairpin junction partway round the lap.
• Stadium Bend. A late-lap corner near Castletown Stadium, close to the paddock and race HQ.

Configurations

Events and race weekends

Billown hosts two main closed-road meetings a year. The Pre-TT Classic Road Races run over three days in late May, during TT practice week, for historic and classic machinery, giving fans on the island early for the TT a second event to watch. The Southern 100 runs over four days each July, with practice and qualifying followed by two full days of racing across solo and sidecar classes, and has been a full international road-race meeting since growing from club status in the mid-1950s.

Getting there and parking

Castletown sits in the south of the Isle of Man, close to Ronaldsway Airport, making it one of the easiest race venues on the island to reach on arrival. Ferries from Heysham and, in summer, Liverpool dock at Douglas, about a 20-25 minute drive or a train ride away on the island's heritage steam railway, which calls at Castletown.

• Isle of Man Airport (Ronaldsway) (IOM) · about 10 min drive

Parking

Parking is available around Castletown for race days, with the paddock and race HQ based at Castletown Stadium; spectators generally find it easier to park and move around than at the much longer TT course.

Because the lap is short and the road network around Castletown is compact, it is realistic to watch from one spot and then walk or drive to another between races, unlike the Mountain Course.

Hotels and camping near Billown Circuit

Castletown itself, along with nearby Port Erin and Port St Mary a short drive further south-west, has the closest B&Bs, hotels and self-catering cottages to the circuit and is the preferred base for regular Southern 100 and Pre-TT Classic visitors. Douglas, about 20-25 minutes away, has the widest range of accommodation on the island and better transport links, and is a common alternative especially if a trip is combined with TT practice week.

Where to look

Castletown for closest proximity to the circuit; Port Erin and Port St Mary as nearby coastal alternatives; Douglas for the widest choice of accommodation.

Track days, driving experiences and lap records

There is no trackday or open-pitlane access to the Billown Circuit: it is a network of public roads carrying ordinary Castletown traffic outside the scheduled closures for the Southern 100 and Pre-TT Classic. Outside race weeks the roads can be driven or ridden at legal speed like any other part of the island's network, but no organisation runs bookable sessions on the layout.

Lap records

Spectator guide

Spectating at Billown is largely free from roadside vantage points around Castletown, and organisers and regular visitors both describe it as friendlier and easier to get around than the much longer TT Mountain Course, with a shorter lap making it simpler to find a good spot and then move to another between races. Some paid grandstand or enclosure options are available near the start/finish and paddock area at Castletown Stadium for those who want closer access.

Seating

Limited grandstand-style seating exists near the start/finish and paddock at Castletown Stadium; most viewing elsewhere on the lap is free roadside standing.

Best places to watch

Church Bends gives a close view of bikes working through a tight, wall-lined chicane, while Ballakeighan and Iron Gate show the pace of the faster sections.

Weather

• Late May (Pre-TT Classic): Cool spring weather typical of the island, highs often 12-15°C with a chance of showers
• July (Southern 100): The island's warmest month, highs typically 16-19°C, generally the most reliable weather of the racing calendar

History of Billown Circuit

Filling a gap left by an airfield

The Southern Motor Cycle Club needed a new home for road racing after losing the use of Andreas Airfield, and in 1955 it put together the Billown Circuit, a triangular lap of public roads around Castletown, running the first Southern 100 race on 14 July that year. What began as a club-level meeting grew quickly: the circuit gained regional status in 1956 and full national status by 1957, and from 1969 it began hosting rounds of British championships, drawing a stronger field of riders to the island each July.

A rider's circuit

Billown earned a reputation among competitors as a demanding but rewarding lap: short enough, at 4.25 miles, to learn thoroughly, but lined almost everywhere by stone walls, hedges and buildings with little run-off, in the same closed-public-road tradition as the TT and Manx Grand Prix. Brian Reid became the first rider to lap the course at over 100mph in 1983, aboard a Suzuki RG500, and lap speeds climbed steadily as bikes and tyres improved over the following decades.

A second event for TT fortnight

From the 1990s the Vintage Motor Cycle Club and other historic-racing bodies began running the Pre-TT Classic Road Races at Billown during TT practice week each May, giving fans already on the island a second meeting to watch, this one for classic machinery rather than current racing bikes. The two events, one modern and one historic, have run alongside each other ever since, cementing Billown's place as the island's second closed-road racing venue after the Mountain Course.

Present day

The Southern 100 remains a full four-day international meeting each July, and 2026 saw Dean Harrison set a new outright lap record of 117.663mph, underlining how competitive it has become even as a supporting fixture to the TT calendar. Regular visitors and organisers promote Billown's shorter lap and friendlier atmosphere as a genuine alternative to the Mountain Course, giving spectators easier access while still watching elite riders who also contest the TT itself.

Frequently asked questions

Other tracks nearby

• St John's Short Course · 14 km · historic circuit (defunct)
• Isle of Man TT Mountain Course · 14 km · public road circuit
• Clypse Course · 17 km · historic circuit (defunct)
• Kirkistown Race Circuit · 68 km · road course
• Bishopscourt Racing Circuit · 75 km · road course
• Anglesey Circuit / Trac Môn · 99 km · road course