The four clocks on the Clock Tower at the Clock Gate of the Belgrade Fortress in Belgrade, Serbia use white hands and Roman numerals on a black dial. The minutes are marked by small white lines on the dial. In addition to the Roman numerals, every full hour has a dot and the four hours 12, 3, 6 and 9 are marked by a larger dot.
Wikipedia has little information on the Clock Gate:
"Southeastern gate in the innermost city wall, it is connected via a bridge to the Inner Stambol Gate. The complex on the southeast ramparts actually consists of two gates, connected by the smaller, side room. The original passage was built for the first time in 1688, after the Austrians conquered Belgrade from the Ottomans. After the Ottomans retook the fortress in 1690, they reconstructed this section of the ramparts and expanded the passage. After the Austrians again conquered Belgrade, from 1717 to 1739, a massive Baroque reconstruction of both the fortress and the city began. A new, Baroque Gate, was dug through, but after another takeover by Ottomans, this gate was walled after 1740 and the Clock Gate became operational again. This is when the clock tower above it was built, which gave the gate its name. It was built by the Venetian architect Andrea Cornaro, and also sometimes called Cornaro's Gate."
Source: en.wikipedia.org/wiki/Gates_of_Belgrade