Bordeaux Recommendations - Other than Winery tours

[WESTEAST]

We will have two days in Bordeaux and plan to spend one day walking around the city taking in the historic part (Golden Triangle) as well as enjoying a nice lunch.  Our second day is undetermined as yet and would appreciate suggestions. Should we visit the Bassins des Lumières or venture to Saint-Émilion?  We have visited many wineries that said, if there was one vineyard to visit, which one would it be?  

 

[AJCM]

Lumieres is fantastic. Held in an old *** submarine base, which had too much concrete to remove, it has been repurposed and the moving art show they project on the walls and reflected in the water is just stunning. An unforgettable experience.