Bay seniors with Lego-obsessed grandkids might want to check out the current exhibit at the low profile Museum of American Heritage in Palo Alto. The exhibit is an annual event and this year boasts re-creations of Bay Area landmarks, railroad displays, castles and miniature cities. $2 admission. If you want to come out of the closet and admit your own fascination with Legos, consider joining the Bay Area User Group. The Museum’s focus is on American invention and technology from 1750-950. Currently they have a major display of early television sets, the kind you will remember from your days watching Hopalong Cassidy. Open Mon-Sun 11-3:30. Free..