As the only means of crossing the river Vltava until 1841, Charles Bridge was the most important connection between Prague Castle and the city's Old Town and adjacent areas.
This land connection made Prague important as a trade route between Eastern and Western Europe.
The bridge was built from Bohemian sandstone. It is said that egg yolks were mixed into the mortar to strengthen the construction of the bridge – just like adding egg yolks when baking to make the dough hold together better.