Walk Along The River Wye 

The Wye flows for about 10.5 miles (17km) from West Wycombe through High Wycombe, Loudwater and Wooburn Green to its confluence with the River Thames at Bourne End. It has two main tributaries, the Hughenden Stream and the Wycombe Marsh Brook which both, like the Wye, are fed from fresh water springs that rise up through the Chiltern chalk.
more information on wikipedia.