The board of county commissioners shall meet, after notice as required by law for meetings of public bodies, at the county seat of each county at quarterly meetings in January, April, July and October in each year and at such other times within the prescribed county as in the opinion of the board the public interests may require. Meetings other than quarterly meetings may be held in the municipality with the largest population concentration in the county, and meetings concerning matters of local interest only may be held in the community affected. All meetings shall be held in a public building owned be [by] the state, county or public schools.