Every visitor to Prague ends up on the Charles Bridge. There is a magnificent view of the castle and the city from there, so it isn’t surprising the bridge is packed all day long. Not many people traipsing across know about the superstition behind its construction.

The tourist guides and books all explain how this bridge was the first stone bridge in Prague. The 1342 flood had damaged the previous one, the Judith bridge¹. King Charles IV recognised the need to have a bridge that would last because this helped trade grow. Locals called it ‘The Stone Bridge’ at the time¹. It was only in 1840 that Prague started calling it ‘Charles Bridge’.

You can see Prague’s love affair with bridges if you follow my walking tour: The Bridges of Prague.

I’ve often strolled across the bridge, jostling tourists, guides and buskers. It is impossible to walk at a reasonable pace, such is the density of people there. Many locals will avoid the bridge completely. I think it’s a shame because it is one of the best views in Central Europe.

King Charles IV was a superstitious sort. As well as being interested in alchemy, he consulted astrologers for their advice. His decision to build a large stone bridge in Prague was one of them.

Firstly, he wanted to know what would be the best time to build a bridge. Astrologers consulted their charts and suggested July 1357. This was a full 15 years after the river demolished the Judith bridge but, according to them, was be the best choice for a bridge because:

1. Mars, a symbol of great achievements, was in the sign of Cancer. The Moon, an alchemical symbol of mercury, was in the sign of Pisces. Both these astrological signs are water signs. The astrologers argued that a water sign is the best sign to have when building a bridge over water.
2. The sun, an alchemical symbol of gold, was in the sign of Leo. Leo is a lion which is the heraldic symbol of the Czech kingdom. You’d want to have gold linked with your own symbol, right?

They narrowed the date to 9 July 1352. King Charles IV consulted the court mathematician Havel of Strahov about the best time to lay the first stone. Havel decided on the following:

• 1357, 9 of July at 5:31 in the morning.
• 1-3-5-7-9-7-5-3-1¹

The number forms a palindrome, a number which is the same whether you read it backwards or forwards. Numerically speaking, this is also a bridge (the numbers ascend from one end and descend the other) which makes it the appropriate number if you want to build a bridge.

Superstitious as he was, and despite the 15-year gap between the old one being destroyed and this date, Charles IV laid the foundation of the bridge at 5:31 in the morning of 9 July 1357.

I’ve been on the bridge in the morning and in the evening, in sun and in snow, in daylight and at night. I always find myself smiling as I cross, thankful for the King’s superstitions which led to this beauty. Who knows what kind of bridge we’d have had if he was a more practical sort?

For more legends and superstition, start walking towards the Old Town Square and marvel at the House of the Golden Well.

The bridge did not collapse as easily as its predecessors did, further validating the King’s choice. He never thought that a stone bridge would be better than the previous wooden ones just because stone is more resilient.

You can also see a double-sunset when on the bridge, if you know when to look

The numbers, as far as Charles IV was concerned, worked because the bridge lasted.

Do you know of any other national monuments built on superstition?

1. Prague, the city and its river; Kateřina Bečková; Karolinum Press 2016; ISBN 978-80-246-3292-6[↩][↩][↩]