A series of terraces sloping down from the tower formed part of the design, and their outline can still be traced between the Observatory and the Queen's House, which faces the hill at the foot. Each terrace was 40 yards wide, and on either side Scotch firs were planted 24 feet apart. These trees were brought by General Monk from Scotland in 1664, and until forty years ago many were standing, and the line of the avenue was still traceable; some of the trunks measured 4 feet in diameter at the ground. Smoke tells so much more on all the coniferous tribes than on the deciduous trees, that they have all now perished. The last dead stump had to be felled some ten years ago. The old Palace was much gone to decay when Charles II. began the alterations, so he pulled it down with the exception of the Queen's House, the only part said to be in good repair, and commenced a vast building designed by Wren, one wing of which only was completed in his reign.