This is a 2 part multi-cache, starting at a fabulous but little known lookout in Castle Hill.
At the listed coordinates you will find a datum plaque that shows the distance from where you are standing to various historical locations around the Hills and Hawkesbury district. Please refer to the panels around the lookout for more information.
The cache can be found within Castle Hill Heritage Park at :
South (Windsor+Wisemans Ferry)/2 degs (3 x Parramatta + Prospect Hill) . [(29 x Sydney Cove) + (Prospect Hill / 4)]
East ((7 x (Prospect Hill+Parramatta)) - 3)degs (Parramatta - 10) . ((Old Windsor Rd/2) - [(5 x Annandale) - (Sydney Cove+4)])
Checksum on decimal minutes: South = 26, East = 12
While you are at GZ, sit a while and enjoy the sounds and the serenity in this urban green space.