A visit out to a theme park is an excellent day out for all the family, with different types of rides and attractions to suit anyone, no matter how scared or wet you want to get! There are quite a few major theme parks across the UK and Europe that are easy to get to and with plenty to do when you get there.
Also you might want to try some of the smaller parks around as they all have individual charm and may have features that you will not find at larger parks such as zoos.
Many of the larger parks are often quite expensive to visit, especially if you have a large family, considering that the entrance in the park does not include lunch or gifts. To make it more affordable, there are often 2 for the price of 1, half price, family deals or other discounts on entrance fees if you look out for vouchers in national newspapers throughout the season.
Most theme parks these days will have a guide to the parks rides and facilities on their website, so you can check the suitability for your family or group before you go.
Also you might want to look at some of the themed hotels within the parks themselves or B&B's close by if you have had a long journey getting there or 1 day just isn't enough!