Alterra - La Mesa, California - 2 Bedroom Apartments with Oversized Walk-In Closets Brand-new Alterra Apartments provide well-balanced living in the heart of La Mesa. Steps from the Grossmont Trolley Station, connecting you to downtown San Diego, Mission Valley, Fashion Valley, Qualcomm Stadium, SDSU or Viejas Arena, all in minutes. Blocks from Grossmont Center, I-8 and Highway 125.