Before proceeding to purchase or condemn real estate for a public park or place, the commission shall determine the location and quantity of the same to be included in any park or place, and cause a survey thereof to be made together with a map showing the real estate to be embraced therein. The map shall be kept by the commissioners in their office, and the boundary lines of every such park or place shall be recorded in a book to be kept by them for that purpose.

The commission shall not be obliged to disclose such locations, surveys or maps to public inspection until it has taken proceedings to condemn real estate or any right or interest therein necessary therefor.