whats a good 3-d modeling program?

[Thermite Paste]

i need a program that will let me make a 3-d model of a park for a school project. it just has to be able to have an almost square piece of land with trees, benches, a volleyball section, a playground, etc. what program is free and easy to do this in?

 

[kevin1211]

anim8or
blender

 

[giarc25]

SketchUp