The hill is shorter today than it used to be - the top of it was carted off to fill in Mill Pond. This had the advantage of making the hilltop easier to build on, and creating more land at Mill Pond - a 2-for-1 deal for developers. Beacon Hill became THE place to live in Boston after the new Massachusetts State House opened here in 1790. Developers created upscale housing on the south side of the hill, which overlooks the Boston Common.