REMOVE

1. Tourist attractions
2. Berlin Wall, Berlin, Germany …
3. Memorials -- Germany
4. Checkpoint Charlie, Berlin, …
5. Heritage tourism -- Germany
6. Dark tourism
7. Berlin
8. GERMANY
9. 1961

WHAT

1. Fences -- England (2)
2. Fountains (2)
3. Heart of the city (2)
4. Public art -- England -- … (2)
5. Railroad stations -- Engl … (2)

WHERE

1. ENGLAND, UK (2)
2. Sheffield, South Yorkshir … (2)

WHO

1. KNIGHT, Chris (2)
2. MUKAIDE, Keiko (2)
3. PAYNE, Brett (2)
4. TYSSEN, Keith (2)
5. not known (2)

WHEN

1. 2007 (2)