Holt's land, to the east of the Tank Stream, had originally been granted to John Connell, a free settler in 1837.

Robertson and Marks with Walter Liberty Vernon, the NSW Government Architect, using funds from the Challis Bequest.

John Henry Challis (1806–1880), an English born merchant and philanthropist left a bequest of £276,000 to The University of Sydney.

[1][2] Challis House is a 12/13 storey reinforced concrete framed structure with 1930s Art Deco style sandstone facades above a polished red granite base to Martin Place and Angel Place with, a bronze coloured mansard roof behind a parapet, and a loft tower to the eastern end.

The original Challis House had a lower ground floor (below pavement level) in the eastern half of the building with a sub-basement below.

The 1937 rebuilding of Challis House signifies a major reconstruction period of many buildings in the Martin Place precinct.

The skilful incorporation of a major part of the original 1907 Challis House facades into the present building is probably unique in New South Wales; technologically it was a significant achievement for its day.

Since 1907 the name Challis House has referred to a building on this site that has been synonymous with Overseas, Australian and New South Wales travel activities.