Hi,
If you're into Beer Festivals and free camping there's an excellent BF on Anglesey, this year its the last day of August and first day of September. Camping is free for those taking tickets for the whole weekend. The best is there is no temptation to drink and drive. You can turn up on the Friday and stay till Monday morning (the power station insist all campers are off site by noon) so it makes a nice Welsh weekend. The venue is the Wylfa Power Station Sports and Social Club, it is a nuclear site so expect to see armed police on site, don't mix it with them. It is run by the Anglesey Central Lions Club and all profits go to charity.
Anglesey Beer Festival Home/Adref will give you the lowdown.
I better declare an interest; you will be phoning me for tickets and my husband is Lions President.
If you are also into Country and Western then the following weekend is a country festival at the same venue with the same camping arrangement. This starts Thursday night and usually goes through to Sunday night, so a few days wild will give an extended and entertaining spell on Anglesey.