amber autumn brown color colour England english fall ferns Great Britain lake lakeside nature park plants red rust Sheffield Park Sussex tawny trees water beech bluebells bulbs Coney's Castle Dorset exercise Fagus flowers footpath fresh green natural path spring trail walk woodland ancient architecture Bonaguil castle defend dordogne flag France french high historical keep old power protection Remains secure security stone strength strong tall tower wall blue fort hill track wild 17th century Argolis battlements defence defense elements fortress Greece landmark Morea nafplio Palamidi Peloponnese ramparts stronghold venetian walls arch hilltop ruins