Henley also known as Henley on Thames is in Oxfordshire and I'd famous for its regatta. This is a genuine quality sporting event with international competitors. It is also a slightly snobby "Society" event where people go to see and be seen. This event is in the Summer but there is much more to Henley than that. In fact I would say unless you are regatta curious avoid the town like the plague during the regatta. Pavements and roads alike are at gridlock and you will have nowhere to park.
The best parts of Henley are the lovely countryside surrounding it and the Thames riverside. There is a park next to river with a good children's adventure playground and plenty of opportunity to find a quiet picnic spot. The towpath here is part of the Thames Path national footpath. I walk between Marlow and Henley which is about 8 miles. There are boat trips in the summer to other towns or just a little way along the river and back. Down near the riverfront there is an old paddlesteamer moored.
A short walk from the town centre is the River and Rowing Museum. This is about the wildlife of the river as well as its sporting and commercial history.
Lots of music fans apparently visit the town because the grave of singer Dusty Springfield is in the church. I was told this by the friendly staff in the Tourist Office. This is tiny and in the Town Hall, the building shown in the Dooyoo picture. This is in the wide partly pedestrianised High street. The rest of the town is very traffic heavy so peace is only really riverside. There is a pub / hotel in the High street, Danesfield House hotel and spa nearby and a touring caravan and cling site at Swiss Farm. I recommend Henley for a taste of the Riverside.