This is the observatory at the Penllergare estate near Swansea, in South Wales, where Victorian astronomer and photographer John Dillwyn Llewelyn took some of the first pictures of the Moon's surface in 1857. It's been crumbling into neglect for years, but now a £2.9m Lottery Heritage Fund project will restore it.
According to this great timeline, Llewlyn and his daughter Thereza took photographs of the Moon's surface from this observatory in 1857, after they had installed a telescope inside. According to the Swansea government, "The observatory will be repaired and restored over the next 18 months. It will also be made accessible along with other attractions in the woods like the terrace gardens, the upper lake, the waterfall and an old stone bridge known as the Llewelyn bridge."