Yellowstone National Park is a truly amazing place. The combination of geysers, vividly coloured pools, waterfalls, deep canyons, mountains, lush river valleys and incredible wildlife make it absolutely unique and in view of this it has been designated a UNESCO World Heritage site. The Park covers a vast area of land in the North West of the US, mainly in the north-west corner of Wyoming but spilling out into the borders of Idaho and Montana. All the main sights are fabulously accessible as there is a loop road around the Park. It does take some investment to get here as there are no international airports in the immediate vicinity of the Park, but there is so much to see and do it makes for a great destination for at least a week (or far longer) or it is easy to combine a trip to Yellowstone into a two centre holiday.
Yellowstone National Park is a great place for a family holiday, especially if you have to travel in the school summer holidays and have had enough of sweating in the high temperatures of the Med or Florida. The balmy mountain air in August will feel like a blessed relief. There is also plenty for couples and groups of friends. If you enjoy art or photography you will be in seventh heaven and I have never met anyone who has been to Yellowstone and not been impressed by the wildlife. So, what are you waiting for? Go, and bore your friends and family silly when you come back showing them the hundreds of pictures you have taken.