There was a party atmosphere as the Royal Navy parachute display team landed with a special anniversary flag, a night swim in the lake was accompanied by jazz musicians.
A host of celebrities gave inspirational talks on the stage, which they shared with many bands and a Rock Choir.
Team GB triathlete and TV presenter Louise Minchin said: “I’m so impressed, especially by the young athletes taking part in the Hever Castle Triathlon today in tough conditions. It was a great effort from everyone who raced.”
The inaugural night swim was spectacularly illuminated at the Italian loggia and pontoon as 120 participants attempted three distances, 400m, 750m and 1500m, along a course that wound around beautifully lit buoys.
There were also five senior triathlons – The Gauntlet Half Iron, Olympic, Sprint-Plus, Super-Sprint and Starter Tri – as well as three different junior races; a half marathon and 10k run; and three swims, over one mile, 5k and 2.5k.
The Gauntlet consisted of a 1.9km swim, 90km bike ride and 21km run, and was won by Ashley Hurdman in a time of 4hr 52min 43sec; Claire Weller was the leading woman, clocking 5:41.58
The Olympic event – 1.5km swim, 40km bike and 10.5km run – was won by Calum Johnson in 2:12.23 with Hannah Munday the first female home in 2:36.00.
The world’s largest junior event of its kind saw 1,500 children tackling various distances.
The children’s triathlon for eight to 10 year olds was 100m swim, 4km bike and 1.3km run, with Finlay Goodman winning in 28min 35sec, with Emma Harding the first girl in 33.21.
The 11 to 12 category – 200m, 4km and 1.8km – was won by William Pridden in 36.44 with Trinity St John Cox the leading girl in 46.34.
And for the 13 to 15 year olds – 300m, 8km and 2.4km – Kai Boggan won in 33.34 with Christina Durbin finishing in 36.46.