Lake Trasimeno is a national park and it has a track that goes all the way round the lake. Each year, in March, people come from all over the world to do the Strasimeno Marathon. This year, the race is being held on the 9th of March. If you are not feeling quite up to doing the ultra marathon (58 km!!), you can always take part in the shorter half marathon, or go for a bike ride instead, or simply sit back and relax whilst others sweat it out 😉 More info here.