2026 Two Tunnels Marathon - Aug 16

Two off-road laps from Brickfields Park through the Two Tunnels Greenway, canal towpath and Bath city centre marathon course in Bath with 250m elevation gain. Mostly flat off-road on old railway grade, with gentle rises rather than real hills - roughly 250m of total ascent across the full two laps, rated moderately undulating. Each lap climbs a slight gradient up to the 408m Devonshire Tunnel and the 1,672m Combe Down Tunnel, then runs the Kennet & Avon Canal towpath, riverside paths past Bath A