We stayed the night in Tremfan Hall, a house which was built for Gwenogfryn Evans, a scholar of medieval Welsh literature and Oxford don who made a fortune out of producing The Library of Wales, bound in leather and printed on parchment.   He established his own printing press to print facsimiles of medieval Welsh manuscripts.   The house, so far as one can tell, is as he left it, except now converted into a hotel, with rather gloomily ornate interiors, animal heads, a tiger rug and ornamental wood carvings.