One lake was so crystal clear that I simply sucked up water when I needed a drink, rather than heading for the support boat.

discovered SwimTrek, a holiday company that takes you on open-water swimming trips around the world, about a year ago. Dreadfully unfit since having children, and with a bad case of middle-aged malaise, I decided things had to change. While other friends tackled marathons, I headed for the pool, and started training in January for my first week-long holiday alone – no kids, lots of sunshine and, most importantly, the sea.

The hosts, Maria and Petri, open their summer holiday home by Lake Sakara to the swimming holiday company Swimtrek, whose professional guides lead the way across several beautiful lakes and rivers of southern Finland. You swim approximately 5km a day (usually in two sessions) but you don’t have to be an Olympic swimmer; so long as you can swim at a steady pace for this distance you will be fine.

If you were inspired by Robson Greens effort after he swam in Snowdonia's Llynn LLydaw, why not create your own Holy Island challenge with a swim from Europe to Asia in the Lord Byron Bicentennial Hellespont Swim in May 2010.

Alcatraz is fifteen metres away, my starting point. A mile and a half across the bay, lies the prize of San Francisco – a thicket of skyscrapers shimmering in the early morning haze. It’s the moment that I’ve been dreading but which hundreds of inmates would once have longed for – a chance to swim to freedom.

The hosts, Maria and Petri, open their summer holiday home by Lake Sakara to the swimming holiday company Swimtrek, whose professional guides lead the way across several beautiful lakes and rivers of southern Finland. You swim approximately 5km a day (usually in two sessions) but you don’t have to be an Olympic swimmer; so long as you can swim at a steady pace for this distance you will be fine.