We report on high angular resolution, high precision spectropolarimetric measurements
of a decaying sunspot. The spot gradually lost its penumbra during the course
of three days. In the late stages of evolution where the only remnant of the spot is a
naked umbra, we nd small-scale inhomogeneities in the magnetic canopy surrounding
it. The inhomogeneities are observed as nger-like structures of weak and nearly
horizontal magnetic elds extending 1-200 from the outer border of the umbra. These
elds are not associated with lamentary structures in continuum intensity, nor with
conspicuous Evershed ows. The Stokes proles emerging from the ngers exhibit
blueshifts which we interpret as upward motions. This previously unknown ne structure
may be related to penumbral eld lines that no longer carry strong Evershed ows
and rise to the chromosphere, producing the disappearance of the penumbra at photospheric
levels.