Petworth was landscaped by Brown for Charles Wyndham, the 2nd Earl Egremont.  Main features of the landscape include a large park and two lakes; work was begun in 1751.   Brown made the lakes out of clay to prevent the water from seeping off; the lakes at Petworth took over two years to construct. Brown also provided extensive treelines to block the view of neighboring farms. 

Below: Brown's plans for Petworth.

    Above and Below: Brown's gentle undulating hills of turf        at Petworth. The clumps of trees draw the eye towards        the key aspects of Brown's masterpiece.

Below: Views of the house at Petworth, the facade and from across Brown's "serpentine" river.

Information taken from source 3,7 and 8.