Early last year, I once grabbed a cute restaurant off the gallery from I don't remember who, and they used a foundation as the plaza for their restaurant that descended into the ground for the entrance - it was a pretty restaurant that looked like it kind of blossomed out of this crater. There were major issues though. The primary issue was that the foundation they used as a plaza - the only area where you could descend the stairs to the front door - didn't have stairs from the street to the higher level, meaning you couldn't even get to the down staircase to enter the establishment. The 2nd and 4th levels were also excessively cramped, and dining was a nightmare. There was also this really awkward outdoor bathroom on the 4th level that was in like a 1x3 room that caused major blockage because Sims often cluttered around the door.
