Alamo Square's elevated and central location makes for a pleasant park - great for picnicking or just relaxing after a long day. Unless the day happens to be the 3rd Sunday of May when Alamo Square's top-of-Hayes-hill becomes a madhouse of spectators, participants and those doing a bit of both in Bay to Breakers :)
Dogs are allowed, but only in the specially-designated area on the east side.
The iconic Painted Ladies watch from the east side of the park. The Lower Haight is a couple blocks away, and the Panhandle a couple beyond that.
Website: http://www.parkscan.org/parks?parkId=62
Wikipedia: http://en.wikipedia.org/wiki/Alamo_Square