 The ridges ran north and east from Messines , 264 feet ( 80 m ) above sea @-@ level at its highest point , past " Clapham Junction " at the west end of the Gheluvelt plateau , 2 @.@ 5 miles ( 4 @.@ 0 km ) from Ypres at 213 feet ( 65 m ) and Gheluvelt which was above 164 feet ( 50 m ) to Passchendaele , 5 @.@ 5 miles ( 8 @.@ 9 km ) from Ypres at 164 feet ( 50 m ) above sea @-@ level , declining from there to a plain further north . <unk> varied from negligible , to 1 : 60 at Hooge and 1 : 33 at Zonnebeke . Underneath the soil was London clay , sand and silt . Since the First Battle of Ypres in 1914 , much of the drainage in the area had been destroyed by artillery @-@ fire , although some repairs had been achieved by army Land Drainage Companies brought from England . The area was considered by the British to be drier than Loos , Givenchy and Plugstreet Wood further south . 
