Possible Clues:

• Large museum on the Mall
• Art museum in Trafalgar Square, London
• *Where to view Calder's 'Vertical Constellation with Bomb'
• Place for public hangings in London square
• State-of-the-art building? Just the opposite!
• A gaol internally repurposed as a building for works of art
• Biggles' friend about to go abroad after land which Nelson turns his back on
• Spectators after horse-race see our pictures here
• State of the art? The opposite, here
• There's a place for public hanging in Trafalgar Square