This undated photo released courtesy Bob Walker showing cats walking along beams in the inside of a home in San Diego Calif. Bob Walker and Frances Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
This undated photo released courtesy Bob Walker showing cats standing on an elaborate set of cat walks inside of a home in San Diego Calif. Bob Walker and Frances Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
This undated photo released courtesy Bob Walker showing cats walking along a custom stairway in the inside of a home in San Diego Calif. Bob Walker and Frances Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
This undated photo released courtesy Bob Walker shows the outside of their house painted a brightly colored hue at the home in San Diego, Calif. Bob Walker and Frances Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
This undated photo released courtesy Bob Walker showing TOM CaT peering throughout a cutout image of a cat inside of a home in San Diego Calif. Bob Walker and Frances Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
This undated photo released courtesy Bob Walker showing Bob Walker and Frances Mooney's home after it was painted to sell in San Diego Calif. Walker and Mooney moved into the house in 1986 and started converting it into a human-sized cat condo with 140 feet of elevated highway, tunnels, ramps, a spiral staircase, rest areas and scenic vistas. It even had a floor to ceiling scratching post. One improvement seemed to lead to another. (AP Photo/Courtesy Bob Walker)
