Most green universities?Watch
If the university is near the beach like Aberystwyth, then that's a plus.
Look at Nottingham, Keele, Exeter and Stirling - or any out-of-town Campus Uni like Bath, UEA, Sussex etc.
Keele is a campus university located in the Staffordshire countryside. Keele is one of the biggest campuses in the UK due to the woods surrounding the centre of campus. An area frequented by students on campus is Keele Hall. Keele Hall is located about a five minute walk from the centre of campus and is on the lovely Italian gardens. These gardens get quite busy during the spring/summer with most students having picnics and bbqs. Located down the hill from Keele Hall, are the Keele woods. These woods host a number of lakes and a range of species of trees. The woods are one of my favorite places to go when I feel a bit stressed or feel like I need some exercise!
Apart from the woods, the centre of campus itself hosts a number of trees, including a collection of flowering blossoms with about 240 different species of blossoms! The campus looks so beautiful with a variety of flowers in full blossom during the spring/summer! Furthermore, most of our halls of accommodation also consist of certain green spaces, where students tend to have bbqs or just lay around in the sun!
I personally think Keele is such a beautiful place and all the outdoor spaces have been so great to spend time with friends and soak up some sun! Especially in the past two years.
I hope this helps! If you have any questions, please don't hesitate to ask!