It might only be 138 kilometres long but the Maratona dles Dolomites (Dolomites Marathon) is easily one of Europes most difficult one day cycling events. Every July thousands of riders from all over the world come together in Northern Italy to tackle the gruelling 138 kilometre course up and down the spectacular mountain passes of the Dolomites. The event sells out every year, with over 30,000 people vying for one of the 9,000 places. National Geographic describes it as "one of the biggest, most passionate, and most chaotic bike races on Earth”.

The route takes riders over 7 major climbs resulting in 4,230m of climbing in only 138km!

• Passo Campolongo (5.8km @ 6.1%)
• Passo Pordoi (9.2km @ 6.9%)
• Passo Sella (5.5km @ 7.9%)
• Passo Gardena (5.8km @ 4.3%)
• Passo Giau (9.9km @ 9.3%)
• Passo Valparola (11.8km @ 6.7%)
• Mür dl giat (the cat wall) (300m @ 13.1%)

To enter the event you must join the ballot between September and November the year before in order to have a chance of making it to the start line.