One of the places I visited for the first time on Culture Night was the RIA on Dawson Street. It's impressively bookish.
The RIA organises public lectures on a range of subjects. Two upcoming lectures look particularly interesting:
1. The annual Hamilton Lecture, on 15th October in TCD, is by Robert C. Merton on the subject Observations on Mathematical Finance in the Practice of Finance. Merton is a Noble-prize winner and one of the leading figures in his field: if you work in finance, there's a good chance you've heard of him. It's a bit like Richard Dawkins turning up to talk about evolution, only with financial maths instead of public excitement or controversy.
2. Also in TCD, on 21st October, is a lecture called "The Anthropocene: a new geological epoch dominated by human activities". It's about climate change; very nice title, I just hope the lecture lives up to it.
Both events are free but booking is required.