The Henry Moore Foundation, established in 1977, nine years before the sculptor's death, is appealing against a prior decision by East Hertfordshire District Council rejecting an application for planning permission.
The proposed development, for Dane Tree House at Perry Green, has soured relations between the foundation and Mary Moore, the artist's only child, who opposes the plan.
David Woolley QC, counsel for the foundation, told the inquiry in Much Hadham that if the enterprise was vetoed, most of the works of a figure 'unequalled' in 'the history of 20th-century art and civilisation' would remain 'in cupboards, locked up in strongrooms or in packing cases'.
Facilities for visitors were 'wholly inadequate'. The proposed buildings were not 'overpowering . . . those who imagine a sort of Disneyland or Alton Towers are fundamentally mistaken'.
Sir Alan Bowness, the foundation's director, dismissed claims by Nathalie Lieven, counsel for Miss Moore and Bruce Brodie, executors of the estate of Moore's wife Irina, that a planned observation tower would defeat Moore's aim that visitors should come upon sculptures by surprise.
The inquiry continues today.