Area 51 is the first area of Duke Nukem Advance, and features three levels.
While being the beginning of Duke Nukem Advance, it is not Duke's first visit to this research center, as the same setting was featured in Duke Nukem 3D: Atomic Edition, see Area 51). The location is again taken over by aliens, who now tries to awaken the Hybrid army of Grays, kept in stasis. The occupying aliens are commanded by Spiderlord, who is the boss battle in the final 3rd level.
Duke Nukem travels through a teleporter leading him deeper into Area 51. In the section he is tasked on locating a Data Disc by General Graves containing intel on a covert operation the Aliens are leading on the creation of a new Alien race.