Cheddar Gorge a tourist destination. In a 2005 poll of "Radio Times" readers, following its appearance on the 2005 television programme "Seven Natural Wonders", Cheddar Gorge was named as the second greatest natural wonder in Britain, surpassed only by Dan yr Ogof caves. The gorge attracts about 500,000 visitors per year. Cheddar is a gorge lying on the southern edge of the Mendip Hills. The maximum depth of the gorge is , with a near-vertical cliff-face to the south, and steep grassy slopes to the north. The B3135 road runs along the bottom of the gorge. The area is underlain by Black
Somerset Valley and to the south, on the clay substrate, are broad valleys which support dairy farming and drain into the Somerset Levels. There is an extensive network of caves, including Wookey Hole, underground rivers, and gorges, including the Cheddar Gorge and Ebbor Gorge. The county has many rivers, including the Axe, Brue, Cary, Parrett, Sheppey, Tone and Yeo. These both feed and drain the flat levels and moors of mid and west Somerset. In the north of the county the River Chew flows into the Bristol Avon. The Parrett is tidal almost to Langport, where there is evidence of two