Those there hills are known as Wittenham Clumps otherwise known as the Sinodun Hills, as viewed from Dorchester on Thames. It was home to a bronze age hill fort and was featured in Time Team and a (home made?) Radiohead music video.
I’m currently in the process of buying a house, the rear garden of which has fantastic view of the clumps (admittedly from the other side).
I’ve noticed that there seems to be a huge increase in the number of Herons around lately. a short paddle up the Thames will usually have me seeing two or three in an evening. This one however was spotted at Hampton Court last year.