It started with a few kittens. But nearly a quarter century later, a California woman has transformed her 4,000-square-foot home into what's believed to be the largest no-cage cat sanctuary and adoption center in the U.S.

An estimated 24,000 cats have been saved so far by the sanctuary, which houses up to 1,000 felines at any given time.

Lynea Lattanzio set up Cat House on the Kings after finding out that many nearby shelters euthanize cats who aren't adopted. As more feral and abandoned cats took up residence in her home, she moved out into a trailer on her 12-acre property.

Lattanzio spent her entire retirement fund on her pet project, which also relies on donations.