At every Turnfest, there is a place where you can see and even sometimes try out the new equipment that manufacturers want to show off. Regular Turner events like the trampoline need to be held indoors with a high ceiling, so those events are held there. All the regions of Germany have their information booths there too. Food, lavatory facilities and emergency care also need to be available. If you have the ticket, there are high level indoor competition events to see. In Frankfurt and Berlin, they held all this in their Messe. The Messe is a large center for conventions and has the facilities to hold a large, sprawling event such as the Turnfest requires. Frankfurt's Messe is famous for its gigantic Book Convention. Mannheim's facility was a large complex combining permanent buildings with tents. It was a bit east of the city, but easy to access with their local trams. Lots to see and take part in, especially for the younger folk.