Amsterdam has a vast array of water canals over 100km in length, around 60 miles. These 165 canals divide the city into a series of small islands connected by over 1200 bridges, with the in 1648; the Torensluis. The majority of canals can be accessed by private boats, group tours, or rental boats with many moored on the canal edges next to houseboats. The citys bridges were built to withstand horse and cart weight of the time, which have since been affected by the trucks and small amount of cars that pass through the canal ring. Complex maintenance work is underway to strengthen certain canal walls and bridges throughout the city.
During the 17th century Amsterdam experienced a massive economic boom, which led to the creation of its concentric canal belt. Four massive ditches were dug around the Dam with each connecting the currents flowing between Amsterdams main sources of water; the river Ij and Amstel. These new constructions were designed to encourage water traffic and meant that goods could be rapidly transported around the city.
