Lady Gaga was in London this week, where she paid a visit to celebrity milliner Philip Treacy. "Just another day in England having tea and hats with my darling friend Philip Treacy. Mint Blonde at Jonathan Ross," the pop star tweeted. Gaga picked up some new headgear at Treacy's studio, including a rose-shaped fascinator and a dollar-sign-topped hat, which she debuted during a Notting Hill shopping spree. Fun fact: Philip Treacy also created Princess Beatrice's famous royal wedding topper. Click through the gallery to browse more of the Irish designer's fanciful creations!