Context: 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 Roman wharfs. At the same site during the reign of King Charles I, river tolls were levied on boats to pay for the maintenance of the bridge.

Question: What's the name of the cave system 
Answer: an extensive network of caves, including Wookey Hole

Question: Name 2 of the county gorges 
Answer: and gorges, including the Cheddar Gorge and Ebbor Gorge

Question: Name some of the county rivers 
Answer: the Axe, Brue, Cary, Parrett, Sheppey, Tone and Yeo

Question: What did King charles levy on river boats 
Answer: King Charles I, river tolls were levied on boats to pay for the maintenance of the bridge.

Question: Where does the Axe river flow into?
Answer: Unanswerable

Question: Which is larger, the Cheddar Gorge or the Ebbor Gorge?
Answer: Unanswerable

Question: What is Somerset's northernmost river?
Answer: Unanswerable

Question: What is the name of one of Somerset's underground rivers?
Answer: Unanswerable

Question: What is Somerset's westernmost river?
Answer: Unanswerable