This building is the tomb of the founder of Karlsruhe - margrave Karl Wilhelm. When he died he was buried in the Konkordia Church that was located right at this place. When in 1807 Karlsruhe's famous architect Weinbrenner tore it down, because he needed more room for the marketplace, he had to find a solution to cover the now unprotected grave. He built a wooden pyramid as a temporary measure. But it became a permanent solution and was rebuilt out of stone in 1825.
The building cannot be visited, although there is a door on the northern side of the pyramid. In all those years the interior was entered only once in 1889 by Grand Duke Friedrich 1st. It is said that he forgot his umbrella inside the pyramid. Maybe future generations will wonder at this special grave good.
Nowadays the building is the landmark of Karlsruhe and one of its symbols.