What is important about Chinatown and Lombard Street?

Hint 1 of 5:

A tour of San Francisco would not be complete without them.

Hint 2 of 5:

You are actually not able to enter any of the buildings.

Hint 3 of 5:

All you can do is look around.

Hint 4 of 5:

Be sure and click on anything you can while you are here.

Hint 5 of 5:

Both Chinatown and Lombard Street have clues to several of the puzzles you
will encounter.