  We have studied the liquid - solid (L-S) phase transition of ^4He confined in
nanoporous glass, which has interconnected nanopores of 2.5 nm in diameter. The
L-S boundary is determined by the measurements of pressure and thermal response
during slow cooling and warming. Below 1 K, the freezing pressure is elevated
to 1.2 MPa from the bulk freezing pressure, and appears to be independent of
temperature. The T-independent L-S boundary implies the existence of a
localized Bose-Einstein condensation state, in which long-range superfluid
coherence is destroyed by narrowness of the nanopores and random potential.
