On the Radgrabenstrasse, at the bottom of the meadows of the Hinterrad mountain pasture
The Ludovika tunnel was opened in 1747 and was first named after Empress Maria Theresia. This tunnel was the first to reach the salt deposit at a greater depth and therefore brought rich yields, which secured the existence of the Ischl salt mine for the next centuries. In the 19th century, it was the visitors’ entrance to the mine and therefore it is not surprising that this entrance has the most artistically significant tunnel portal. On both sides of the entrance, there are two obelisks commemorating the visits of Emperor Francis I and his wife Maria Ludovika in 1808 and 1814, which also resulted in the renaming to Ludovika Tunnel. The portal received its present form after the emperor's visit in 1814 (1818?). Due to the construction of the agricultural road around 2008, the terrain was greatly changed and part of the lateral retaining wall was destroyed.
The monumental tunnel portal is made of perfectly crafted limestone squares. The display wall is divided by pilasters, and is raised like an attic above the basket-arched entrance, creating the impression of a fortress gate. The year of construction (1747) was inserted into the arch keystone later, and the lettering LUDOVIKA was added above the year recently. The obelisks are made of polished granite. They are on limestone pedestals and were originally topped by gilded imperial crowns on cushions. Marble plaques with German and Latin homage poems are embedded in the granite. The German verses are free translations of the then very common Latin lines. On the left pylon, the year 1814 is engraved in Roman numerals. On the right pylon, there is a Latin poem with highlighted Roman numbers for the year 1808.
In 2019, the tunnel portal was last renovated in an exemplary manner by the Cultural Heritage Society of Bad Ischl (Ischler Heimatverein).