The Tate Britain is a photographers delight with loads of interesting architectural spaces both inside and out. The recently constructed spiral staircase, domed entry hall, vaults and large open spaces provide interesting light conditions for photographers of all kinds.
The main art collection is completely free and you are allowed to take photographs everywhere except in the charged exhibition spaces. Its the last day of the Richard Deacon sculpture show which includes some lyrical timber constructions. (you would need to get a ticket for this part however)
I plan to set a series of themed photography challenges for the group and hope you can join in the fun!