ibausil — Internationale Baustofftagung
16–18 September 2026
Three days in September, every few years since 1964
Three days that fill the congress hall with concrete chemistry — and have done since 1964.
Long Night of Sciences
The city's research institutions open their doors for an evening in November.
In 60 days
13 November 2026 · 18:00 Uhr
For one evening in November the city's universities, institutes and companies open their doors — experiments, presentations and lectures, run for anyone curious enough to come out after dark.
Weimar is read almost entirely through the eighteenth century, and it is also a place where several institutions do current work in engineering, media, conservation and design. This is the one evening a year when that half of the town is the thing on display rather than the backdrop to it.
The foundation runs a programme of its own in the Anna Amalia Library's study centre. At the last edition that meant visitors could research alongside the staff, experiment, watch and ask — a research library doing its research in public, which is not a thing it otherwise offers.
16–18 September 2026
Three days in September, every few years since 1964
Three days that fill the congress hall with concrete chemistry — and have done since 1964.
23–24 September 2026
Two days in September, every year
Germany's tenancy lawyers meet here every year — and both sides of the argument organise it together.
25–26 September 2026
Two days in late September
The state's dental profession takes the congress hall for two days in September.
Dates to be confirmed
Early November
A regional cancer-medicine society brings its annual congress to the hall in November.
Organiser
Klassik Stiftung Weimar
Facts checked against the organiser on 2 September 2026
Platz der Demokratie 1, 99423 Weimar
The foundation's own share of the night runs in the library's study centre — a research library doing its research in public for one evening.