The triumphal arch in honor of the Prince Elector Karl Theodor, located at Heidelberg's very east, was erected between 1775 and 1781 and designed by Nicolas de Pigage.

When the foundation-stone was laid on October 2, 1775, the Prince Elector personally attended the celebration. He took a personal interest in the construction work and had the architect draw a new plan, which finally unified elements of the preceding three sketches.

The final result was a neo-classical building following the tradition of Roman triumphal arches, crowned by four lions, the traditional symbols of the "Kurpfalz". Portraits of the Prince Elector and his wife are located under the princely hat in the center of the top facing the city from the west. The centerpiece pointing beyond Heidelberg contains a written dedication topped by a weapon trophy with the Kurpfalz (Palatinate) Coat of Arms. The sculptures were created by Peter Simon Lamine. The triumph arch was never totally completed.