This is what we found on Wikipedia regarding the Retro Rewind:

The Rewind Festival is an annual music festival that takes place in Temple Island Meadows, Remenham, Berkshire near Henley-on-Thames, England, Capesthorne Hall, Cheshire, England, and Scone Palace, Perthshire in Scotland. It was first held in August 2009.

Originally called "80s Rewind Festival", it showcases bands and solo artists that had success in the 1980s and as such is also known as the 80's Rewind Festival. As well as music, in 2009 the site also featured a fun fair, street entertainment and artists from The Comedy Store.

The festival is run by The Rival Organisation and Into The Groove, and was started after the success of one-off 1980s retro shows of previous years.

Since its creation a number of additional attractions were included at the festival, including a weekend camp site, glamping, firework displays, theme bars, silent disco, roller disco, the Big Sing, live karaoke stage, and the Friday night welcome party.

In 2019 the capacities of the festivals were Scotland: 30,000, South: 40,000, and North: 20,000.