  We study the topological content of the vacuum of SU(2) pure gauge theory
using lattice simulations. We use a smoothing process based on the
renormalization group equation. This removes short distance fluctuations but
preserves long distance structure. The action of the smoothed configurations is
dominated by instantons, but they still show an area law for Wilson loops with
an unchanged string tension. The average radius of an instanton is about 0.2
fm, at a density of about 2 fm${}^{-4}$.
