The otherwise calm surface of this American lake - a shrinking oasis in a high desert basin - is broken by strange, tower-like rock formations. Name the state, known for its surfing beaches and laid-back lifestyle, where the lake is found. The winner will receive a 19 inch (49cm) Briggs & Riley (www.briggs-riley.com) carry-on suitcase in black, worth £260 (see second image, above). Entries close at 4pm on Wednesday, July 18. The answer to last week's quiz was Lebanon. Mrs Andrea Jefferson from Northamptonshire wins the suitcase.