The Chain Bridge (Széchenyi Lánchíd), built in 1849, was the first connection between the then independent cities of Buda and Pest (the cities were merged in 1872). It was the initiative of Count István Széchenyi, who brought a steam engine to Hungary and founded the Hungarian Academy of Sciences, and was designed by British engineers William and Adam Clark.

Although it has the word "chain" directly in its name, it is in fact a classic suspension bridge, but architecturally it is one of the most beautiful in Europe, with a span of 202 metres, at the time of its commissioning it was even one of the largest in the world. Parts of the massive steel chains weighing over 5 000 tonnes are attached to the massive stone gates, which form the bridge's most striking feature.

Széchenyi Bridge is also the first of 8 modern bridges that connected the two cities of Buda and Pest, making it Budapest's most famous bridge.

On the Buda side, the Buda Tunnel under Castle Hill with its magnificent entrance portal connects to the bridge. Its construction began not long after the bridge was completed and was finished in 1857.