the valley continued to attract notable people: major sir thomas mitchell, one of australia's best-known explorers built the first house at stanwell park; supreme court judge john fletcher hargrave later owned and holidayed in the area, his inheritance coming to lawrence hargrave, one of the world's most important aviation pioneers of the 1890s in the lead-up to powered man flight. he performed his most important experiments at stanwell park. lawrence hargrave moved to hillcrest house, having inherited it from his brother ralph hargrave, in 1893. it is on the road up to the stanwell park railway station.