The Prague Astronomical Clock, also known as the Prague Orloj, is one of the most popular tourist attractions in the city of Prague, Czech Republic. Located in the heart of the Old Town Square, it is a remarkable medieval astronomical clock that has been functioning since the 15th century.

History:
The Prague Astronomical Clock was first installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still in operation. It was designed by master clockmaker Mikuláš of Kadaň and was later enhanced by Jan Šindel, a professor of mathematics and astronomy.

Features:
The clock consists of three main components: the astronomical dial, the hourly show of the Twelve Apostles, and the calendar dial. The astronomical dial displays various astronomical details such as the position of the sun and moon, zodiac signs, and the phases of the moon. The hourly show features a procession of the Twelve Apostles, with figurines appearing from the windows above the clock face. The calendar dial shows the months, days, and Czech name days.

Tips for Visitors:
1. Be prepared for crowds: The Prague Astronomical Clock is a popular attraction, so it can get quite crowded, especially during peak tourist seasons. Arriving early in the morning or later in the evening can help you avoid the biggest crowds.

2. Witness the hourly show: The hourly show of the Twelve Apostles is a spectacle not to be missed. Make sure to be in front of the clock a few minutes before the hour to have a good view. It's a fascinating display of craftsmanship and engineering.

3. Take a guided tour: To fully appreciate the history and significance of the Prague Astronomical Clock, consider joining a guided tour. Knowledgeable guides can provide you with interesting insights and stories related to the clock's construction and its importance to Prague's history.

4. Explore the surrounding area: The Old Town Square, where the clock is located, is a vibrant and picturesque area with many other attractions nearby. Take some time to explore the beautiful architecture, visit the nearby Church of Our Lady before Týn, or enjoy a meal at one of the traditional Czech restaurants in the square.

The Prague Astronomical Clock is not only a remarkable piece of medieval engineering but also a symbol of Prague's rich history and cultural heritage. Its intricate design and fascinating hourly show make it a must-visit attraction for any tourist in Prague.