Recent demolitions are Boardwalk in 2006, Stardust in March 2007, New Frontier in November 2007 and Riviera in June 2016 Sahara closed in May 2011, reopening late 2014 after partial remodeling as SLS Las Vegas. In recent times, the businesses have been taken over by big conglomerates, many of the older places have been knocked down to make way for huge showy entertainment complexes aimed at attracting the whole family, though the rate of development has now decreased. Click each casino for more detailsGambling was legalized in Las Vegas in 1931, but large-scale construction of casinos did not begin until after World War 2, and for many years they were dominated by individual property holders, often with Mafia connections.