Barangaroo's Headland Park is a "dream job" and will be unique to the world, renowned American architect Peter Walker says.

The proposed design for the unused site at East Darling Harbour on Sydney's foreshore was released on Saturday and will turn back time to circa 1836.

More than two hectares of landfill along the water's edge of the site will be chipped away to recreate a sandstone shoreline not seen for more than 170 years.

The Headland Park will be situated at the northern end of the site and occupy 6.7 hectares of the total 22ha area.

It resembles a massive car park and will be buried under more than 350,000 cubic metres of soil used to elevate the site level with where it was once cut away from the existing headland.