Question: In what country did Irvine Gerald Sellar develop the second-tallest free-standing structure?

Passages:
Ostankino Tower (Russian: Останкинская телебашня , "Ostankinskaya telebashnya") is a television and radio tower in Moscow, Russia, owned by the Moscow branch of unitary enterprise Russian TV and Radio Broadcasting Network.  Standing 540.1 m tall, Ostankino was designed by Nikolai Nikitin.  It is currently the tallest free-standing structure in Europe and 11th tallest in the world.  The tower was the first free-standing structure to exceed 500 m in height.  Ostankino was built to mark the 50th anniversary of the October Revolution.  It is named after the Ostankino district of Moscow in which it is located. Wall boxes are a type of post box or letter box found in many countries including France, the United Kingdom, the Commonwealth of Nations, Crown dependencies and Ireland.  They differ from pillar boxes in that, instead of being a free-standing structure, they are generally set into a wall (hence the name) or supported on a free-standing pole, girder or other stable structure.  In the UK, UK Dependent Territories, Colonies and former Colonies and in many former British Empire countries, wall boxes usually bear the initials of the reigning monarch at the time the box was made.  The first UK wall boxes were erected in 1857 in Shrewsbury and Market Drayton. The Tallinn TV Tower ("Tallinna teletorn") is a free-standing structure with an observation deck, built to provide better telecommunication services for the 1980 Moscow Summer Olympics regatta event (see Sailing at the 1980 Summer Olympics).  It is located near the suburb Pirita, six km north-east of the Tallinn city center.  With its 314 m (1030.2 ft), the TV Tower is the tallest building in Tallinn.  The tower was officially opened on 11 July 1980.  The viewing platform at a height of 170 metres was open to the public until 26 November 2007, when it was closed for renovation.  Having been repaired, the tower began receiving visitors again on 5 April 2012.  The building is administered by the public company Levira (formerly "Estonian Broadcasting Transmission Center Ltd") and is a member of the World Federation of Great Towers. The Liaoning Broadcast and Television Tower (Chinese: 辽宁广播电视塔, Pinyin: liáoníng guǎngbō diànshì tǎ) is a tall free-standing structure used for communication.  It was built in 1989 in Shenyang, China and is 305.5 m tall.  Within the "disk" of the tower, accessible through an elevator, there is an in-door observation deck, rotating restaurant, and a small bar.  On the top of the disk is an outdoor observation deck.  This tower is in World Federation of Great Towers. The Shard, also referred to as the Shard of Glass, Shard London Bridge and formerly London Bridge Tower, is a 95-storey skyscraper in Southwark, London, that forms part of the London Bridge Quarter development.  Standing 309.7 m high, the Shard is the tallest building in the United Kingdom, the fourth-tallest building in Europe and the 96th-tallest building in the world.  It is also the second-tallest free-standing structure in the United Kingdom, after the concrete tower at the Emley Moor transmitting station. This list of tallest buildings in Toronto ranks skyscrapers in the Canadian city of Toronto, Ontario by height.  The tallest structure in Toronto is the CN Tower, which rises 553 m .  The CN Tower was the tallest free-standing structure on land from 1975 until 2007.  However, it is not generally considered a high-rise building as it does not have successive floors that can be occupied.  The tallest habitable building in the city is First Canadian Place, which rises 298 metres (978 ft) tall in Toronto's Financial District and was completed in 1975.  It also stands as the tallest building in Canada. Q1 (an abbreviation of Queensland Number One) is a supertall skyscraper in Surfers Paradise, on the Gold Coast, Queensland.  It lost its title as the world's tallest residential building to the 337-metre The Marina Torch in Dubai on 29 April 2011.  It is now the sixth tallest residential tower in the world and is the tallest building in Australia and the Southern Hemisphere and the second-tallest free-standing structure in the Southern Hemisphere, behind the Sky Tower in Auckland, New Zealand.  The Q1 officially opened in November 2005. The CN Tower (French: "Tour CN" ) is a 553.3 m concrete communications and observation tower in downtown Toronto, Ontario, Canada.  Built on the former Railway Lands, it was completed in 1976, and held the record for the world's tallest free-standing structure for 32 years from 1975–2007 and was the world's tallest tower until 2009 being overtaken by Burj Khalifa and Canton Tower, respectively.  It is now the third tallest tower in the world and remains the tallest free-standing structure in the Western Hemisphere, a signature icon of Toronto's skyline, and a symbol of Canada, attracting more than two million international visitors annually. Irvine Gerald Sellar (9 September 1934 – 26 February 2017) was an English fashion retailer, turned property developer.  He was the founder of the Sellar Property Group, and the developer of The Shard. A guy-wire, guy-line, or guy-rope, also known as simply a guy, is a tensioned cable designed to add stability to a free-standing structure.  They are used commonly in ship masts, radio masts, wind turbines, utility poles, fire service extension ladders used in church raises and tents.  A thin vertical mast supported by guy wires is called a guyed mast.  Structures that support antennas are frequently of a lattice construction and are called "towers".  One end of the guy is attached to the structure, and the other is anchored to the ground at some distance from the mast or tower base.  The tension in the diagonal guy-wire, combined with the compression and buckling strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures.  They are installed radially, usually at equal angles about the structure, in trios and quads.  As the tower leans a bit due to the wind force, the increased guy tension is resolved into a compression force in the tower or mast and a lateral force that resists the wind load.  For example, antenna masts are often held up by three guy-wires at 120° angles.  Structures with predictable lateral loads, such as electrical utility poles, may require only a single guy-wire to offset the lateral pull of the electrical wires, at a spot where the wires change direction.

Supporting sentences:
 He was the founder of the Sellar Property Group, and the developer of The Shard.  It is also the second-tallest free-standing structure in the United Kingdom, after the concrete tower at the Emley Moor transmitting station.