Hundreds of runners from 28 countries have begun running in what’s claimed to be the world’s toughest mountain race.

A total of 298 athletes begun hot-footing it between Conwy and Cardiff castles on Monday in the hope of winning the Dragon’s Back.

They will cover 236 miles (380 km) over six days over a route that reaches ascents of 3,800m (12,467ft).

Organisers warn those considering taking part: “This is no trail race.”