It seems to be on the right side of Paris, so there's that; Google indicates a few options with public transport, just over an hour.

I see I made a mistake: the metro station nearby is called Cour St Emillion.

The hotel has elevators and the metro has escalators.

This is close to a metro station (Clemenceau), and just outside a lively neighbourhood of restaurants and breakfast places, and there's a nice park too for when you need to touch grass. A pedestrian bridge across the Seine leads to the Bibliothèque nationale.

Plenty of cheap and decent hotels in Paris. I usually stay in an 'apart hotel' meaning no breakfast buffet but a microwave and/or small kitchen in your room. This way you can cook your own food when you need quiet time. My favourite chain is Adagio, eg Adagio Paris Bercy Village.

Well he did call it "Hidden in plain sight", which always struck me as an odd expression.

'It's a lost map!'
'Where did you find it?'
'In the Map Drawer, in the Map Room of the Map Library'.
OH is seriously thinking about doing a talk on data and discovery entitled 'why we keep biscuits in the biscuit tin'. Seems appropriate.