Image copyright Snowdonia Marathon

If running a marathon was not hard enough, imagine doing one around the roads of Wales' tallest mountain.

But that is exactly what 2,900 runners will be doing on Saturday as they tackle this year's Snowdonia Marathon.

Places for the gruelling race, which starts and finishes at the bottom of Snowdon and has a climb of 2,750ft (838m), were snapped up in two hours.

Race co-ordinator Jayne Lloyd said runners return "year on year" due to its location and Snowdonia's "beauty".

The 26.2 mile (42km) route from Llanberis in Gwynedd takes the runners up the notorious Pen-y-Pass ascent, drops into the spectacular Nant Gwynant valley to Beddgelert, before another epic climb and trail descent back into Llanberis.

Now in its 36th year, the event has twice been voted the best marathon in the UK and organisers estimate it will raise about £1m for charity.

Team Bath's Daniel Jones won last year's race in two hours and 36 minutes with Hayley Munn, of Northampton Road Runners, winning the ladies race.

However, the race's gruelling climbs meant that more than 45 did not finish at all.

A number of road closures will be in place along the route which starts and ends in Llanberis, including the A4086 Llanberis Pass.

Local car parks are expected to be busy with race registration taking place near the Electric Mountain visitor centre.