Covent Garden’s Carmen still sings in the Underground

From an Aigul Akhmetshina interview with Farah Nayeri in the NY Times:

‘I love to sometimes spontaneously sing in the London Underground, shock people. On a recent holiday in Dubai, I was on the beach and people asked me what I did. When I said I was an opera singer, they said they’d never been at an opera, and I said “Now you will be.” I sang the “Habanera” aria from “Carmen” for them right there on the beach. They had never heard it, and they said, “Oh, I really should go.”

‘I do that often, if I see that people don’t have the opportunity and were never introduced to classical music. They feel the vibration of your voice so closely that they really think: maybe I should experience this.’

Which tube station?