After the Ottomans retook the fortress in 1690, they reconstructed this section of the ramparts and walled the gate.
After the Austrians again conquered Belgrade, from 1717 to 1739, a massive Baroque reconstruction of both the fortress and the city began.
It is a mechanical clock, and the original hands are kept in the Institute for the Cultural Monuments Protection in Belgrade.
In the late 19th century and the 1900s, along the rampart three auxiliary guard houses were constructed by the Serbian army.
The earthen mound which covered the rampart and the gates was removed to reduce moisturizing of the inside rooms.
It was also expected to reclaim two side rooms which were thought to be collapsed, but it turned out they were actually never finished, even though the openings for the doors and windows are made on the gate's inner walls.
A temporary, protective wooden eave was built above the entrance of the Clock Gate.
Due to the lack of proper experts, the clock remained out of order,[7] until November 2021.
The inner gate had a defensive balcony, machicolation, with a niche below for the city defender saint's icon.
Partially reconstructed in 1938, today it hosts the observatory of the "Ruđer Bošković" astronomical society.
[9] The gate itself was reconstructed in 2020, including works on outer facade, inner walls and stabilized statics of the object.
The towers were roofed with bricks, while the protective arched wall was enhanced with the earthen embankment.
Works also include moisture problems solving, revitalization of the walls and their statics, and reconstruction of the side rooms which will become usable again.
Due to its unusual name and unique appearance within the fort's complex, it is one of the most distinct gates.
There was an inscription on the gate: "Charles VI, Roman emperor, august, apostle of the true faith against Christian enemies, built this gate, a magnificent structure, after conquering the famed city of Belgrade".
Cartouche held an ornamental motive which represented boar's head pierced with an arrow.
[18] During the World War II occupation, the Nazi fringe organization Ahnenerbe conducted numerous surveys and diggings in the fortress, including specific search for the gate.