We are, as you know, huge fans of the work of Richard Serra. We would give our right arm to be able to see this. (We are left-handed.)
(The above link also takes you to an accompanying slide show, which doesn't really do the work a whole lot of justice but does manage to convey the scent of Paris in the spring.)
The only Richard Serra we have actually seen is a little, but beautiful, piece owned by the gallery across the road from where we work.