Bordering the Strand, the residential East End Historic District has scores of pretty old houses, from simple cottages to Greek Revival mansions, some of which are often featured on the annual Historic Homes Tour. A good guide and map is available on the district's website or at the erratically open visitor center on the southwest corner of 15th and E.
The East End Historical District Association sometimes hosts walking tours. Contact newwalkingtour@eastendhistoricdistrict.org for information.