The wall remains we see here are from the very first fortifications from the 17th century. At that time, people were most worried about attacks from the land side, and therefore several fortifications were built outside Kvarnholmen to stop the enemy.
It was an important hub, where the access roads from both north and south met. There was also a customs house where all goods were cleared through customs.
When the customs were removed, and Västerport lost its significance as the city's gate to the countryside, the Tullbron bridge was built. In 1852, it was inaugurated. At that time there was a bridge fee, where one had to pay different amounts depending on the vehicle. And the bridge fee was paid in the small dome. So the Öresund bridge is not a new invention with its fees!