This unusual, eight-sided, cupola-topped house dates from 1861 and is maintained by the National Society of Colonial Dames of America. Its design was based on a past theory that people living in a space of this shape would live longer, healthier lives. Inside is a small museum where you'll find Early American furniture, portraits, silver, pewter, looking glasses, and English and Chinese ceramics. There are also some historic documents, including signatures of 54 of the 56 signers of the Declaration of Independence. Even if you're not able to visit the inside, this atypical structure is worth a look from the outside.

Copyright: Excerpted from Frommer's San Francisco 2009, (c) 2008, Wiley Publishing, Inc.

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