Question: The 2014 Abu Dhabi Grand Prix was held at a circuit designed by who?

Context paragraphs:
2014 Abu Dhabi Grand Prix: The 2014 Abu Dhabi Grand Prix (formally known as the 2014 Formula 1 Etihad Airways Abu Dhabi Grand Prix) is a Formula One motor race that was held at the Yas Marina Circuit on 23 November 2014.  The race was the nineteenth and final round of the 2014 season, the 916th World Championship race, and marked the sixth running of the Abu Dhabi Grand Prix.

Yas Marina Circuit: The Yas Marina Circuit (Arabic: حلبة مرسى ياس) is the venue for the Abu Dhabi Grand Prix.  The circuit was designed by Hermann Tilke, and is situated on Yas Island, about 30 minutes from the capital of the UAE, Abu Dhabi.  Yas Marina is the second Formula One track in the Middle East, with the first being in Bahrain.  A two-day GP2 Asia Series test was held to officially open the circuit, which was held a week before the 2009 Abu Dhabi Grand Prix.  It also hosted the opening event for the Australian V8 Supercars series, the Yas V8 400, in February 2010.  Outside motorsport the circuit was used for the final stage of the inaugural Abu Dhabi Tour cycle race in 2015.  The circuit has FIA Grade 1 license.

2016 Abu Dhabi Grand Prix: The 2016 Abu Dhabi Grand Prix (formally known as the 2016 Formula 1 Etihad Airways Abu Dhabi Grand Prix) was a Formula One motor race held on 27 November 2016 at the Yas Marina Circuit in Abu Dhabi, United Arab Emirates.  The race was the final round of the 2016 season and determined the 2016 World Drivers' Championship.  It marked the eighth running of the Abu Dhabi Grand Prix and the eighth time that the race had been run as a World Championship event since the inaugural season in .

2011 Abu Dhabi Grand Prix: The 2011 Abu Dhabi Grand Prix (formally the Etihad Airways Abu Dhabi Grand Prix) was the eighteenth and penultimate round of the 2011 Formula One season.  It was held on 13 November 2011 at the Yas Marina Circuit on Yas Island, a man-made island on the outskirts of Abu Dhabi in the United Arab Emirates.  It was the third running of the Abu Dhabi Grand Prix.  As is customary with the race, it was the only twilight Grand Prix of the 2011 Formula One season, with a start time of 17:00 .

2012 Abu Dhabi Grand Prix: The 2012 Abu Dhabi Grand Prix (formally the 2012 Formula 1 Etihad Airways Abu Dhabi Grand Prix) was a Formula One motor race held on 4 November 2012 at the Yas Marina Circuit, Yas Island, Abu Dhabi, United Arab Emirates.  It was the eighteenth round of the 2012 Formula One season and the fourth Abu Dhabi Grand Prix.  The 55-lap race was won by Lotus driver Kimi Räikkönen after starting from fourth position.  Fernando Alonso finished second in a Ferrari with his championship rival Sebastian Vettel third for Red Bull.

2010 Abu Dhabi Grand Prix: The 2010 Abu Dhabi Grand Prix (formally the Etihad Airways Abu Dhabi Grand Prix) was a Formula One motor race held on 14 November 2010 at the Yas Marina Circuit on Yas Island, an island on the outskirts of Abu Dhabi in the United Arab Emirates.  It was the 19th and last round of the 2010 Formula One season.  The 55-lap race was won by Red Bull driver Sebastian Vettel after starting from pole position.  Lewis Hamilton finished second in a McLaren, and teammate Jenson Button completed the podium, in third place.

2009 Abu Dhabi Grand Prix: The 2009 Abu Dhabi Grand Prix (formally the I Etihad Airways Abu Dhabi Grand Prix) was the seventeenth and final Formula One motor race of the 2009 Formula One season.  It took place on 1 November 2009 at the 3.45-mile Hermann Tilke-designed Yas Marina Circuit.  It was the inaugural Abu Dhabi Grand Prix and also the first ever day-night Grand Prix (starting at 17:00, with sunset at 17:43 on raceday).  The race was won by Sebastian Vettel for Red Bull, with polesitter Lewis Hamilton (driving for McLaren) having retired due to a brake failure.  This was also the last race for Kazuki Nakajima and Giancarlo Fisichella and the BMW Sauber and Toyota teams.

2015 Abu Dhabi Grand Prix: The 2015 Abu Dhabi Grand Prix (formally known as the 2015 Formula 1 Etihad Airways Abu Dhabi Grand Prix) was a Formula One motor race held at the Yas Marina Circuit on 29 November 2015.  The race was the nineteenth and final round of the 2015 season, and marked the seventh running of the Abu Dhabi Grand Prix as a round of the World Championship since its inception in .

2013 Abu Dhabi Grand Prix: The 2013 Abu Dhabi Grand Prix (formally known as the 2013 Formula 1 Etihad Airways Abu Dhabi Grand Prix) was a Formula One motor race that was held at the Yas Marina Circuit on 3 November 2013.  The race was the seventeenth round of the 2013 season, and marked the 5th running of the Abu Dhabi Grand Prix.

2017 Abu Dhabi Grand Prix: The 2017 Abu Dhabi Grand Prix (formally known as the 2017 Formula 1 Etihad Airways Abu Dhabi Grand Prix) is a Formula One motor race scheduled to be held on 26 November 2017 at the Yas Marina Circuit in Abu Dhabi, United Arab Emirates.  The race is due to be the final round of the 2017 season and will determine the 2017 World Drivers' Championship.  It mark the ninth running of the Abu Dhabi Grand Prix and the ninth time that the race has been run as a World Championship event since the inaugural season in .

Supporting paragraphs: 2014 Abu Dhabi Grand Prix Yas Marina Circuit
Answer: Hermann Tilke