lack of long term trend data of seawall effects due to a relatively short duration of data records; modelling limitations and comparisons of different projects and their effects being invalid or unequal due to different beach types; materials; currents; and environments. Lack of maintenance is also a major issue with seawalls. In 2013, more than 5,000 feet (1,500 m) of seawall was found to be crumbling in Punta Gorda, Florida. Residents of the area pay hundreds of dollars each year into a seawall repair program. The problem is that most of the seawalls are over a half century old and are being destroyed by only heavy downpours. If not kept in check, seawalls lose effectiveness and become expensive to repair. History and examples Seawall construction has existed since ancient times. In the first century BCE, Romans built a seawall / breakwater at Caesarea Maritima creating an artificial harbor (Sebastos Harbor). The construction used Pozzolana concrete which hardens in contact with sea water. Barges were constructed and filled with the concrete. They were floated into position and sunk. The resulting harbor / breakwater / seawall is still in existence today – more than 2000 years later. The oldest known coastal defense is believed to be a 100-meter row of boulders in the Mediterranean Sea off the coast of Israel. The boulders were positioned in an attempt to protect the coastal settlement of Tel Hreiz from the sea rise following the last glacial maximum. Tel Hreiz was discovered in 1960 by divers searching for shipwrecks, but the row of boulders was not found until storms cleared the sand cover in 2012. More recently, seawalls were constructed in 1623 in Canvey Island, UK, when great floods of the Thames estuary occurred, prompting the construction of protection for further events in this flood prone area. Since then, seawall design has become more complex and intricate in response to an improvement in materials, technology and an understanding of how coastal processes operate. This section will outline some key case studies of seawalls in chronological order and describe how they have performed in response to tsunami or ongoing natural processes and how effective they were in these situations. Analysing the successes and shortcomings of seawalls during severe natural events allows their weaknesses to be exposed, and areas become visible for future improvement. Canada The Vancouver Seawall is a stone seawall constructed around the perimeter of Stanley