Can anyone figure out what on earth this giant egg-like thing is, near Acton, Massachusetts?

Update: As ever our readers have come to the rescue, and it seems that this is the Annursnac Hill Reservoir, a covered water storage facility sitting on the top of Annursnac Hill. There’s a fantastic birds-eye view of it over at Live Local, although Safari users be aware that it doesn’t work with your browser yet, but it works just fine in Firefox.

Thanks to Jesse.

This is the Foster City sign in (you guessed it) Foster City, California. Founded in the 60s, Foster City is built entirely on landfill in what was previously marshland. Matt Schneider says that during the 1989 Loma Prieta Earthquake the reclaimed land made it feel like “being in a building on soup”.

Anyway, these giant letters are pretty cool - compare them to the size of the houses!

Thanks to William Kendrick, Mazin Jalili, Matt Schneider