All of the above names are usually left in english ( in almost every book, brochure or other publication) and you should keep it that way...
otherwise what would the British be calling to the Römer in Frankfurt or to the Dom in Cologne??
What you can do however is to write a translation (if you must) between brackets...
so here goes:

Tufnell park
London Bridge = London Brücke
Tate Modern
Tower Bridge = Turm-Brücke
Tower of London = London Turm
Globe Theatre = Globe Theater
Camden Market = Camden Markt
National Maritime Museum = Marine Museum
Queen’s House = Königins-Haus
Old Royal Observatory
Greenwich Park
Greenwich Market = greenwich Markt
Cutty Sark
Millenium Dome
Notting Hill Gate
Houses of Parliament
St. Paul’s Cathedral = St.Pauls Kathedrale
Dr Johnson’s House =Dr.Johnsons Haus


Please take a look at these links and see for yourself that in almost 100% of the cases although the texts are German the English names have been kept in the original.

london.htm
... Marine - Museum. Eine Turm-Brücke, mit den zwei geschmückten ... zuerst baute. Der Weisse
Turm, ist Gestein aus der ... des Turmes von London. Spätere wurden andere ...
land.heim.at/waldviertel/240067/london.htm

Maschieren sie
... kommen sie an allen berühmten Sehenswürdigkeiten vorbei ! Ich persönlich habe ... Vorbei
an Westminster Abbey, Houses of Paliament, Big Ben, 10, Dowining ...
www.finanzenlinks.de/touren/tourentexte/tourensitetext.htm

and a lot more at:
http://www.google.com/search?hl=en&lr=&safe=off&q= sehensw�r...

You never ever translate things like London Bridge, Tower Bridge, Millennium Dome etc. They are proper names, so they stay as they are.

Tufnel Park = Der Tufnell-Park -- As far as I know, Tufnell Park is an area in North London, so it stays as it is.
London Bridge = Die London Brücke -- No, this stays as it is!
Tate Modern = Das Tate Modern(-Museum) -- Tate Modern is a gallery, so you would simply say "die Tate Modern"
Tower Bridge = Die Turm-Brücke -- Never ever! It stays as it is: "die Tower Bridge"
Tower of London = Der Londoner Turm -- No way! This is known as "der Tower" oder "der Tower von London" in German.
Globe Theatre = Das Globe-Theater -- Possible, or "das Globe Theatre"
Camden Market = Der Camdener Markt -- Preferably: der Markt in Camden or im Londoner Stadtteil Camden
National Maritime Museum = Das Schiffahrtsmuseum -- Preferably: leave as it is because it is the museum's name
Queen’s House = Das Haus der Queen -- Wrong! The Queen has many "houses", so this doesn't work. It is a proper name, so it has to stay as it is.
Old Royal Observatory = Die Alte Königliche Sternwarte -- A proper name, so don't translate it
Greenwich Park = Der Greenwich-Park -- Just like Hyde Park, I would leave it as "Greenwich Park". You could aslo say "der Park in Greenwich", depending on your sentence.
Greenwich Market = Der Greenwich Markt -- see Camden Market
Cutty Sark = Das Cutty Sark -- *die* Cutty Sark
Millenium Dome = Die Millennium-Kuppel -- Wrong! It is "der Millennium Dome"
Notting Hill Gate = Das Notting-Hill-Tor -- This is not translated. It stays as Notting Hill Gate
Houses of Parliament = Die Parlamentsgebäude -- Normally "das Parlament(sgebäude)" or leave as "Houses of Parliament"
St. Paul’s Cathedral = Der Dom von St.Paul -- No! It stays as it is.
Dr Johnson’s House = Das Haus des Dr. Johnson -- Possible, or leave as it is.