Complex sentence: The Beefsteak Club that still meets in London at 9 Irving Street, off Leicester Square, was founded in 1876 in rooms above the Folly Theatre, in King William IV Street.
Split into simpler sentences: The Beefsteak Club that still meets in London is in Irving Street, off Leicester Square. It was founded in 1876 in rooms above the Folly Theatre, in King William IV Street.