The province of Zeeland is in fact one big river delta, situated as it is at the mouth of several big rivers. Most of the province lies beneath sea level and was reclaimed from the sea by the people over time. What used to be a muddy landscape flooded at high tide and reappearing at low tide, first became the scene of small man-made hills that would stay dry at all times. Later the people of the province would connect the hills by creating dikes, which lead to a chain of dry land that later grew into bigger islands and gave the province its current shape. The shape of the islands has been changing through time both by the hands of man and nature. The North Sea flood of 1953 claimed vast amounts of land that were only partially reclaimed. The subsequent construction of the Delta Works also changed the face of the province. The infrastructure (although very distinct by the amount of bridges, tunnels and dams) hasn't shaped the province as much as the geography of the province has shaped the infrastructure. The dams, tunnels and bridges that are currently a vital part of the province's road system were constructed over the space of decades and came to replace old ferry lines. The final touch to this process came in 2003 when the Westerschelde tunnel was opened. It was the first solid connection between both banks of the Westerschelde and ended the era of water separating the islands and peninsulas of Zeeland.