Possible Clues:

• Prehistoric ruin on Salisbury Plain
• Antique stones set in a ring
• Salisbury Plain monument
• Wiltshire attraction
• A female replaces article in platform at old monument
• Site near an outdoor recording session in 'Help!'
• Rock group that's been around for a long time
• Wiltshire monument
• Free? Then go see round new tourist attraction
• Possible ancient astronomical observatory