The Painted Hall, Old Royal Naval College, Greenwich.
This ceiling and walls were painted by Sir James Thornbill between 1708 & 1727. The "Sistine Chaple" of England where Admiral Nelson was laid in state for 3 days when his body was brought back from the Battle of Trafalgar.
It's all being renovated at a cost of £8.5M.
The scaffolding gives a platform just 2mtrs from the ceiling. This is the closest you'll ever get to this masterpiece. If you have the chance I would highly recommend a visit.