The Prague astronomical clock, or Prague Orloj, received its first known mention in official records, marking a significant point in the evolution of timekeeping. Installed on the southern wall of the Old Town Hall in Prague, the clock was an elaborate installation featuring not only a mechanical timekeeper but also an astronomical dial that illustrated the position of celestial bodies. The clock was designed by Mikuláš de Kadaně and was notable for its advanced mechanics for the time, providing not just the time of day but also various astronomical information, including the phases of the moon and zodiac signs.

The clock’s design incorporated an intricate array of moving figures known as the Apostles, which would become a central aspect of its appeal. Each hour, the clock offered a performance where figures representing the twelve Apostles would appear in a procession. This feature drew crowds of both locals and tourists, captivated by the combination of artistry and engineering that the clock represented. Beyond its technical attributes, the clock served as a symbol of civic pride for Prague, demonstrating the city's wealth and cultural significance during the late Middle Ages.

Over the years, despite being partially damaged and undergoing restorations, the clock preserved its reputation as a remarkable work of art and science. Its significance lies in how it blended practical functionality with a cultural statement, becoming an icon of Prague itself, and attracting continuous interest from visitors to this day.