▁and ▁botan ists . ▁The ▁centre ▁opened ▁in ▁ 1 9 8 9 ▁and ▁under w ent ▁a ▁major ▁upgrade ▁in ▁ 2 0 0 4 . ▁As ▁of ▁ 2 0 0 8 ▁around ▁over ▁ 1 5 , 0 0 0 ▁people ▁visited ▁the ▁centre ▁ann ually . ▁SN H ▁have ▁way mark ed ▁a ▁ 1 . 5   km ▁path ▁known ▁as ▁the ▁Ty rie ▁Tra il , ▁and ▁there ▁several ▁other ▁paths ▁across ▁the ▁reserve . ▁ ▁Ge ology ▁and ▁ge omorph ology ▁ ▁The ▁cl iffs ▁that ▁border ▁the ▁reserve ▁formed ▁around ▁ 4 0 0 ▁million ▁years , ▁and ▁are ▁composed ▁primarily ▁of ▁mainly ▁and es ite ▁and ▁bas alt . ▁They ▁were ▁formerly ▁sea ▁cl iffs , ▁formed ▁at ▁the ▁end ▁of ▁the ▁last ▁Ice ▁Age ▁when ▁the ▁sea ▁level ▁rose ▁due ▁to ▁mel ting ▁ice . ▁The ▁changes ▁in ▁sea ▁level ▁over ▁time ▁can ▁be ▁seen ▁in ▁the ▁raised ▁be aches ▁along ▁the ▁base ▁of ▁the ▁cl iffs . ▁The ▁coast line ▁at ▁St ▁C yrus ▁N NR ▁continues ▁to ▁change ▁constantly , ▁and ▁as ▁of ▁ 2 0 0 8 ▁the ▁d unes ▁of ▁the ▁reserve ▁were ▁continu ing ▁to ▁grow . ▁The ▁course ▁of ▁the ▁River ▁North ▁E sk ▁has ▁also ▁alter ed ▁over ▁time , ▁and ▁the ▁old ▁channel ▁that ▁the ▁river ▁took ▁prior ▁to ▁ 1 8 7 9 ▁remains ▁visible ▁several ▁hundred ▁metres ▁to ▁the ▁north ▁of ▁the ▁current ▁course . ▁The ▁position ▁of ▁river ▁mouth ▁continues ▁to ▁moves