Back in the early planning days of Tower Bridge, one of the standout construction challenges was building it downstream from London Bridge without disrupting river traffic. In response, a public competition took place with the goal of generating some novel design ideas. In the end, it was decided that Tower Bridge would be operated by steam-powered hydraulics, and subsequently, oil and electricity, that could drive the bascules up as a ship approached.

Today, visitors can still witness this amazing sight, as there are roughly 800 vessels that pass through the bascules each year. We also recommend taking a trip to the bridge at nighttime to experience the landmark lit up.