Württemberg Mausoleum, Neoclassical mausoleum in Untertürkheim, Germany

The Württemberg Mausoleum stands on the summit of the Rotenberg above the Neckar valley. Giovanni Salucci's 1820–1824 design follows Palladio's Villa Rotonda: a cylindrical central building with four identical porticos facing the cardinal directions, each reached by a staircase of four perrons. The dome is capped by a glass skylight, and its iron-and-glass cupola is among Germany's earliest all-iron structures.

Catherine Pavlovna died in 1819 after a lip blister became infected, and William I had the ruined ancestral castle of the House of Württemberg demolished that same year. He chose an unsolicited Neoclassical design by court architect Giovanni Salucci over entries by Leo von Klenze and others; the cornerstone was laid in May 1820 and the building finished in 1824. William died in 1864 and was buried beside her.

The mausoleum held Russian Orthodox services from 1825 to 1899, and one is still celebrated each Whit Monday. The interior is divided like a Russian church into vestibule, nave and chancel, a layout chosen for Queen Catherine's Orthodox faith. In wall niches stand colossal Carrara marble statues of the four Evangelists, carved by Johann Heinrich Dannecker, Theodor Wagner, Johann Nepomuk Zwerger and after designs by Bertel Thorvaldsen.

The mausoleum is open to visitors from April through November, accessible via a footpath from the southern side of the hill. A gentle ramp leads to the entrance, making the visit feasible for most people despite the hillside location.

The crypt holds two sarcophagi of Carrara marble, not one: William I rests beside Catherine Pavlovna, while their daughter Marie Friederike Charlotte has her own. The king's body arrived after sunset on 30 June 1864, carried from Rosenstein Palace per his testament. The dome's iron-and-glass cupola is among Germany's earliest all-iron structures.