The Lakefront is a separate expansion area.
Completing the Portal will give you 2 free land Expansions. Clicking on the Drawbridge or the Lakefront Tab on top of the Menu will send you there. The Drawbridge is allowed to be stored, once completed.
When it was made available, the lakefront area had its own type of people: "Vacationers". You had to use Lakefront Buildings to increase the Population and Population Allowed of Vacationers. Decorations in that category give a double bonus to the lakefront housing and businesses.
Expansions here and in the main city are still determined by your total game Population. You are free to put any type of building in the Lakefront area.
Basic listings of Lakefront items:
Opening the Lakefront also entered you in the Lakefront Sweepstakes, which ended on September 25, 2012.