HOUSTON — As Houston prepares to host Super Bowl 51 on Feb. 5, its leaders are eager to show off a makeover that has transformed the city since it last hosted the game more than a decade ago.

The Houston that awaits nearly 140,000 Super Bowl visitors and millions of television viewers is the result of an ambitious effort aimed at turning the city into a world-class destination. In contrast to its past reputation as an urban dead zone after dark, Houston now includes a greater array of restaurants, high-rises, green space, and cultural and entertainment venues.

“They are in for a big positive surprise,” Mayor Sylvester Turner said of out-of-towners who may still have an earlier perception of Houston.