Although the tiny establishment was moved in its entirety, wooden booths and all, to its current location near Yale's campus in 1975, it still looks pretty much the way it did when the place was last renovated, in 1929. Jeff Lassen, the fourth-generation owner, makes the patties from a secret combination of five different cuts of beef. They're formed by hand, topped with raw onion slices, and enclosed in a metal grate, which he slides into one of three cast-iron broilers forged in 1898. The burgers emerge nicely browned and rare in the center; they're slipped between two pieces of toasted Pepperidge Farm white bread along with a slice of tomato. You can request cheese, but that's it: no pickles, lettuce, or ketchup. Louis' Lunch leaves those bells and whistles to the new kids on the block.