Federal
State
Mass GIS - Aerial Photos
Mass GIS - Shape Files (Need GIS Software to view)
Metropolitan District Commission
City of Cambridge
Community Development Department - Environmental & Transportation Planning
Organizations
The Charles River Watershed Association
Measurements and Conversions
Length
1 millimeter (mm) = 0.03937 inch = 0.1 centimeter
1 centimeter (cm) = 0.39 inch = 0.01 meter
1 inch (in) = 2.54 centimeters = 0.083 foot
1 foot (ft) = 0.3048 meter = 0.33 yard
1 yard (yd) = 0.9144 meter
1 meter (m) = 3.2808 feet = 1.0936 yards
1 kilometer (km) = 1000 meters = 0.6214 mile (statute) = 3281 feet
1 mile (statute) (ml) = 5280 feet = 1.6093 kilometers
1 mile (nautical) (ml) = 6076 feet = 1.8531 kilometers
Area
1 square centimeter (cm2) = 0.0001 square meter = 0.15550 square inch
1 square inch (in2) = 0.0069 square foot = 6.452 square centimeters
1 square foot (ft2) = 144 square inches = 0.0929 square meter
1 square yard (yd2) = 9 square feet = 0.8361 square meter
1 square meter (m2) = 1.1960 square yards = 10.764 square feet
1 acre (ac) = 43,560 square feet = 4046.95 square meters
1 hectare (ha) = 10,000 square meters = 2.471 acres
1 square kilometer (km2) = 1,000,000 square meters = 0.3861 square mile
1 square mile (mi2) = 640 acres = 2.590 square kilometers