There are several places to stay in Jena, and almost all of them are within walking distance of the conference venue. Jena is small. We have had particularly good experiences with Zur Noll („Zur Noll” Jena | Gasthaus & Hotel), Eulensteins (Boutique Hotel Jena) and Vielharmonie (Start – VielHarmonie Jena) and so far no negative experiences with any of the other hotels.
As Jena is small, we recommend booking early. If you can’t find a place, Weimar is also highly recommended. It is a very beautiful city and can be reached by train in 20 minutes.