The building was erected as a theatre by architect Wilhelm Vernukken in 1603/1606. The commissioner was Landgraf Moritz, who named the Ottoneum after his son Otto. Today, a natural history museum is housed here. Well-known collection pieces are a Xylotheque and the Ratzenberger Herbarium. [German]
The Saalburg is a reconstructed Roman fort in Hesse. Inside its walls, a museum tells about the life of the soldiers along the border. The castellum was a part of the Upper Germanic-Rhaetian Limes. Today the remains of the Limes are enlisted as UNESCO World Heritage Site.
The Nerobergbahn was built in 1888 as a funicular railway driven by water counterbalancing and is still operated with this technology. It connects the Nerotal Valley with the Neroberg Hill, a lookout high over Wiesbaden. [German]
Several German railway stations offer model railway layouts. After putting in a 1-Euro-coin, children (and their parents) can control the miniature trains. The dioramas are pretty large and full of details. I took this photo at the central station of Frankfurt am Main.
Fun detail seen in Kassel: A figure standing on top of a sphere inside a church tower. Its a sculpture created by the artist Stephan Balkenhol. The traffic lights are not art, I was just standing at a pedestrian crossing and there was no time for a better position.
After World War II, a large part of Kassel was rebuilt in the style of the 50ties. So if you are interested in the architecture of this period, a walk through Kassel is an appropriate way to learn more about it.