Original: Sydenham Hill is one of the highest locations in London; 109 metres (357 ft) above sea level (spot height on Ordnance Survey Map); and the size of the palace and prominence of the site made it easy to identify from much of London.
Simplified: Sydenham Hill, where the Crystal Palace was, is one of the highest locations in London and the size of the palace made it easy to see from Central London.