Move southwest a bit and you can see the green space of the Parc Leopold, intruded on by the oval shape of part of the European Parliament's complex (the "Caprice des Dieux" building). But look for a moment at the three buildings between the Parliament and the ponds in the park. The southernmost of the three I know well - the former Solvay library, it is now a conference centre where I have attended many events (and even organised one). The other two are typical Art Nouveau buildings, rather beautiful to look at but not part of my daily life.
Well, I shall look more closely at the northernmost of the three buildings next time I go through the park. Now a school, it was built as the Institut Solvay by the Belgian industrialist and philanthropist in 1895, and from 1912 hosted the Solvay Conferences. It was in this building in 1927 that Einstein, mocking Bohr's attachment to randomness in quantum mechanics, asked him sardonically "...ob der liebe Gott würfelt?" (usually translated as the flat statement, "God does not play dice"). Bohr's reply, that it was not up to Einstein to tell God what to do, tends to get lost in standard accounts of the exchange.
See pictures and a home movie of the conference, here.